Merge branch 'master' into rpc_poll_ids

2016-02-27 15:34:02 +01:00 · 2016-02-27 15:34:02 +01:00 · f1538ebc76
commit f1538ebc76
parent 2947a1415b db9774fb62
23 changed files with 1278 additions and 411 deletions
--- a/README.md
+++ b/README.md
@ -15,77 +15,28 @@

 ### Building from source

-##### Ubuntu 14.04, 15.04, 15.10
+First (if you don't already have it) get multirust:

+- Linux:
 ```bash
-# install rocksdb
-add-apt-repository ppa:ethcore/ethcore
-apt-get update
-apt-get install -y --force-yes librocksdb-dev
-
-# install multirust
-curl -sf https://raw.githubusercontent.com/brson/multirust/master/blastoff.sh | sh -s -- --yes
-
-# install beta
-multirust update beta
-
-# download and build parity
-git clone https://github.com/ethcore/parity
-cd parity
-
-# parity should be build with rust beta
-multirust override beta
-
-# build in release
-cargo build --release
-```
-
-##### Other Linux
-
-```bash
-# install rocksdb
-git clone --tag v4.1 --depth=1 https://github.com/facebook/rocksdb.git
-cd rocksdb
-make shared_lib 
-sudo cp -a librocksdb.so* /usr/lib 
-sudo ldconfig 
-cd ..
-
-# install rust beta
 curl -sf https://raw.githubusercontent.com/brson/multirust/master/blastoff.sh | sudo sh -s -- --yes
-
-# install beta
-multirust update beta
-
-# download and build parity
-git clone https://github.com/ethcore/parity
-cd parity
-
-# parity should be build with rust beta
-multirust override beta
-
-# build in release
-cargo build --release
 ```

-##### OSX with Homebrew
+- OSX with Homebrew:
+```bash
+brew update && brew install multirust
+```
+
+Then, download and build Parity:

 ```bash
-# install rocksdb && multirust
-brew update
-brew install rocksdb
-brew install multirust
-
-# install beta
-multirust update beta
-
-# download and build parity
+# download Parity code
 git clone https://github.com/ethcore/parity
 cd parity

-# use rust beta for building parity
+# parity should be built with rust beta
 multirust override beta

+# build in release mode
 cargo build --release
 ```
-
--- a/ethcore/src/block.rs
+++ b/ethcore/src/block.rs
@ -144,20 +144,20 @@ impl IsBlock for ExecutedBlock {

 /// Block that is ready for transactions to be added.
 ///
-/// It's a bit like a Vec<Transaction>, eccept that whenever a transaction is pushed, we execute it and
+/// It's a bit like a Vec<Transaction>, except that whenever a transaction is pushed, we execute it and
 /// maintain the system `state()`. We also archive execution receipts in preparation for later block creation.
-pub struct OpenBlock<'x, 'y> {
+pub struct OpenBlock<'x> {
 	block: ExecutedBlock,
 	engine: &'x Engine,
-	last_hashes: &'y LastHashes,
+	last_hashes: LastHashes,
 }

 /// Just like OpenBlock, except that we've applied `Engine::on_close_block`, finished up the non-seal header fields,
 /// and collected the uncles.
 ///
 /// There is no function available to push a transaction. If you want that you'll need to `reopen()` it.
-pub struct ClosedBlock<'x, 'y> {
-	open_block: OpenBlock<'x, 'y>,
+pub struct ClosedBlock<'x> {
+	open_block: OpenBlock<'x>,
 	uncle_bytes: Bytes,
 }

@ -169,9 +169,9 @@ pub struct SealedBlock {
 	uncle_bytes: Bytes,
 }

-impl<'x, 'y> OpenBlock<'x, 'y> {
+impl<'x> OpenBlock<'x> {
 	/// Create a new OpenBlock ready for transaction pushing.
-	pub fn new(engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: &'y LastHashes, author: Address, extra_data: Bytes) -> Self {
+	pub fn new(engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes, author: Address, extra_data: Bytes) -> Self {
 		let mut r = OpenBlock {
 			block: ExecutedBlock::new(State::from_existing(db, parent.state_root().clone(), engine.account_start_nonce())),
 			engine: engine,
@ -259,7 +259,7 @@ impl<'x, 'y> OpenBlock<'x, 'y> {
 	}

 	/// Turn this into a `ClosedBlock`. A BlockChain must be provided in order to figure out the uncles.
-	pub fn close(self) -> ClosedBlock<'x, 'y> {
+	pub fn close(self) -> ClosedBlock<'x> {
 		let mut s = self;
 		s.engine.on_close_block(&mut s.block);
 		s.block.base.header.transactions_root = ordered_trie_root(s.block.base.transactions.iter().map(|ref e| e.rlp_bytes().to_vec()).collect());
@ -275,16 +275,16 @@ impl<'x, 'y> OpenBlock<'x, 'y> {
 	}
 }

-impl<'x, 'y> IsBlock for OpenBlock<'x, 'y> {
+impl<'x> IsBlock for OpenBlock<'x> {
 	fn block(&self) -> &ExecutedBlock { &self.block }
 }

-impl<'x, 'y> IsBlock for ClosedBlock<'x, 'y> {
+impl<'x> IsBlock for ClosedBlock<'x> {
 	fn block(&self) -> &ExecutedBlock { &self.open_block.block }
 }

-impl<'x, 'y> ClosedBlock<'x, 'y> {
-	fn new(open_block: OpenBlock<'x, 'y>, uncle_bytes: Bytes) -> Self {
+impl<'x> ClosedBlock<'x> {
+	fn new(open_block: OpenBlock<'x>, uncle_bytes: Bytes) -> Self {
 		ClosedBlock {
 			open_block: open_block,
 			uncle_bytes: uncle_bytes,
@ -307,7 +307,7 @@ impl<'x, 'y> ClosedBlock<'x, 'y> {
 	}

 	/// Turn this back into an `OpenBlock`.
-	pub fn reopen(self) -> OpenBlock<'x, 'y> { self.open_block }
+	pub fn reopen(self) -> OpenBlock<'x> { self.open_block }

 	/// Drop this object and return the underlieing database.
 	pub fn drain(self) -> JournalDB { self.open_block.block.state.drop().1 }
@ -332,7 +332,7 @@ impl IsBlock for SealedBlock {
 }

 /// Enact the block given by block header, transactions and uncles
-pub fn enact<'x, 'y>(header: &Header, transactions: &[SignedTransaction], uncles: &[Header], engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: &'y LastHashes) -> Result<ClosedBlock<'x, 'y>, Error> {
+pub fn enact<'x>(header: &Header, transactions: &[SignedTransaction], uncles: &[Header], engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock<'x>, Error> {
 	{
 		if ::log::max_log_level() >= ::log::LogLevel::Trace {
 			let s = State::from_existing(db.clone(), parent.state_root().clone(), engine.account_start_nonce());
@ -350,20 +350,20 @@ pub fn enact<'x, 'y>(header: &Header, transactions: &[SignedTransaction], uncles
 }

 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
-pub fn enact_bytes<'x, 'y>(block_bytes: &[u8], engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: &'y LastHashes) -> Result<ClosedBlock<'x, 'y>, Error> {
+pub fn enact_bytes<'x>(block_bytes: &[u8], engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock<'x>, Error> {
 	let block = BlockView::new(block_bytes);
 	let header = block.header();
 	enact(&header, &block.transactions(), &block.uncles(), engine, db, parent, last_hashes)
 }

 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
-pub fn enact_verified<'x, 'y>(block: &PreVerifiedBlock, engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: &'y LastHashes) -> Result<ClosedBlock<'x, 'y>, Error> {
+pub fn enact_verified<'x>(block: &PreVerifiedBlock, engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock<'x>, Error> {
 	let view = BlockView::new(&block.bytes);
 	enact(&block.header, &block.transactions, &view.uncles(), engine, db, parent, last_hashes)
 }

 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header. Seal the block aferwards
-pub fn enact_and_seal(block_bytes: &[u8], engine: &Engine, db: JournalDB, parent: &Header, last_hashes: &LastHashes) -> Result<SealedBlock, Error> {
+pub fn enact_and_seal(block_bytes: &[u8], engine: &Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<SealedBlock, Error> {
 	let header = BlockView::new(block_bytes).header_view();
 	Ok(try!(try!(enact_bytes(block_bytes, engine, db, parent, last_hashes)).seal(header.seal())))
 }
@ -384,7 +384,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(&mut db);
 		let last_hashes = vec![genesis_header.hash()];
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, &last_hashes, Address::zero(), vec![]);
+		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), vec![]);
 		let b = b.close();
 		let _ = b.seal(vec![]);
 	}
@ -398,14 +398,14 @@ mod tests {
 		let mut db_result = get_temp_journal_db();
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(&mut db);
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, &vec![genesis_header.hash()], Address::zero(), vec![]).close().seal(vec![]).unwrap();
+		let b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), vec![]).close().seal(vec![]).unwrap();
 		let orig_bytes = b.rlp_bytes();
 		let orig_db = b.drain();

 		let mut db_result = get_temp_journal_db();
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(&mut db);
-		let e = enact_and_seal(&orig_bytes, engine.deref(), db, &genesis_header, &vec![genesis_header.hash()]).unwrap();
+		let e = enact_and_seal(&orig_bytes, engine.deref(), db, &genesis_header, vec![genesis_header.hash()]).unwrap();

 		assert_eq!(e.rlp_bytes(), orig_bytes);

--- a/ethcore/src/block_queue.rs
+++ b/ethcore/src/block_queue.rs
@ -285,18 +285,24 @@ impl BlockQueue {
 	}

 	/// Mark given block and all its children as bad. Stops verification.
-	pub fn mark_as_bad(&mut self, hash: &H256) {
+	pub fn mark_as_bad(&mut self, block_hashes: &[H256]) {
 		let mut verification_lock = self.verification.lock().unwrap();
+		let mut processing = self.processing.write().unwrap();
+
 		let mut verification = verification_lock.deref_mut();
-		verification.bad.insert(hash.clone());
-		self.processing.write().unwrap().remove(&hash);
+
+		verification.bad.reserve(block_hashes.len());
+		for hash in block_hashes {
+			verification.bad.insert(hash.clone());
+			processing.remove(&hash);
+		}
+
 		let mut new_verified = VecDeque::new();
 		for block in verification.verified.drain(..) {
 			if verification.bad.contains(&block.header.parent_hash) {
 				verification.bad.insert(block.header.hash());
-				self.processing.write().unwrap().remove(&block.header.hash());
-			}
-			else {
+				processing.remove(&block.header.hash());
+			} else {
 				new_verified.push_back(block);
 			}
 		}
@ -304,10 +310,10 @@ impl BlockQueue {
 	}

 	/// Mark given block as processed
-	pub fn mark_as_good(&mut self, hashes: &[H256]) {
+	pub fn mark_as_good(&mut self, block_hashes: &[H256]) {
 		let mut processing = self.processing.write().unwrap();
-		for h in hashes {
-			processing.remove(&h);
+		for hash in block_hashes {
+			processing.remove(&hash);
 		}
 	}

--- a/ethcore/src/client.rs
+++ b/ethcore/src/client.rs
@ -21,7 +21,7 @@ use util::panics::*;
 use blockchain::{BlockChain, BlockProvider, CacheSize};
 use views::BlockView;
 use error::*;
-use header::BlockNumber;
+use header::{BlockNumber, Header};
 use state::State;
 use spec::Spec;
 use engine::Engine;
@ -230,85 +230,127 @@ impl Client {
 		self.block_queue.write().unwrap().flush();
 	}

+	fn build_last_hashes(&self, header: &Header) -> LastHashes {
+		let mut last_hashes = LastHashes::new();
+		last_hashes.resize(256, H256::new());
+		last_hashes[0] = header.parent_hash.clone();
+		let chain = self.chain.read().unwrap();
+		for i in 0..255 {
+			match chain.block_details(&last_hashes[i]) {
+				Some(details) => {
+					last_hashes[i + 1] = details.parent.clone();
+				},
+				None => break,
+			}
+		}
+		last_hashes
+	}
+
+	fn check_and_close_block(&self, block: &PreVerifiedBlock) -> Result<ClosedBlock, ()> {
+		let engine = self.engine.deref().deref();
+		let header = &block.header;
+
+		// Verify Block Family
+		let verify_family_result = verify_block_family(&header, &block.bytes, engine, self.chain.read().unwrap().deref());
+		if let Err(e) = verify_family_result {
+			warn!(target: "client", "Stage 3 block verification failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
+			return Err(());
+		};
+
+		// Check if Parent is in chain
+		let chain_has_parent = self.chain.read().unwrap().block_header(&header.parent_hash);
+		if let None = chain_has_parent {
+			warn!(target: "client", "Block import failed for #{} ({}): Parent not found ({}) ", header.number(), header.hash(), header.parent_hash);
+			return Err(());
+		};
+
+		// Enact Verified Block
+		let parent = chain_has_parent.unwrap();
+		let last_hashes = self.build_last_hashes(header);
+		let db = self.state_db.lock().unwrap().clone();
+
+		let enact_result = enact_verified(&block, engine, db, &parent, last_hashes);
+		if let Err(e) = enact_result {
+			warn!(target: "client", "Block import failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
+			return Err(());
+		};
+
+		// Final Verification
+		let closed_block = enact_result.unwrap();
+		if let Err(e) = verify_block_final(&header, closed_block.block().header()) {
+			warn!(target: "client", "Stage 4 block verification failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
+			return Err(());
+		}
+
+		Ok(closed_block)
+	}
+
 	/// This is triggered by a message coming from a block queue when the block is ready for insertion
 	pub fn import_verified_blocks(&self, io: &IoChannel<NetSyncMessage>) -> usize {
-		let mut ret = 0;
-		let mut bad = HashSet::new();
+		let max_blocks_to_import = 128;
+
+		let mut good_blocks = Vec::with_capacity(max_blocks_to_import);
+		let mut bad_blocks = HashSet::new();
+
 		let _import_lock = self.import_lock.lock();
-		let blocks = self.block_queue.write().unwrap().drain(128);
-		let mut good_blocks = Vec::with_capacity(128);
+		let blocks = self.block_queue.write().unwrap().drain(max_blocks_to_import);
+
 		for block in blocks {
-			if bad.contains(&block.header.parent_hash) {
-				self.block_queue.write().unwrap().mark_as_bad(&block.header.hash());
-				bad.insert(block.header.hash());
+			let header = &block.header;
+
+			if bad_blocks.contains(&header.parent_hash) {
+				bad_blocks.insert(header.hash());
 				continue;
 			}

-			let header = &block.header;
-			if let Err(e) = verify_block_family(&header, &block.bytes, self.engine.deref().deref(), self.chain.read().unwrap().deref()) {
-				warn!(target: "client", "Stage 3 block verification failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
-				self.block_queue.write().unwrap().mark_as_bad(&header.hash());
-				bad.insert(block.header.hash());
-				break;
-			};
-			let parent = match self.chain.read().unwrap().block_header(&header.parent_hash) {
-				Some(p) => p,
-				None => {
-					warn!(target: "client", "Block import failed for #{} ({}): Parent not found ({}) ", header.number(), header.hash(), header.parent_hash);
-					self.block_queue.write().unwrap().mark_as_bad(&header.hash());
-					bad.insert(block.header.hash());
-					break;
-				},
-			};
-			// build last hashes
-			let mut last_hashes = LastHashes::new();
-			last_hashes.resize(256, H256::new());
-			last_hashes[0] = header.parent_hash.clone();
-			for i in 0..255 {
-				match self.chain.read().unwrap().block_details(&last_hashes[i]) {
-					Some(details) => {
-						last_hashes[i + 1] = details.parent.clone();
-					},
-					None => break,
-				}
-			}
-
-			let db = self.state_db.lock().unwrap().clone();
-			let result = match enact_verified(&block, self.engine.deref().deref(), db, &parent, &last_hashes) {
-				Ok(b) => b,
-				Err(e) => {
-					warn!(target: "client", "Block import failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
-					bad.insert(block.header.hash());
-					self.block_queue.write().unwrap().mark_as_bad(&header.hash());
-					break;
-				}
-			};
-			if let Err(e) = verify_block_final(&header, result.block().header()) {
-				warn!(target: "client", "Stage 4 block verification failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
-				self.block_queue.write().unwrap().mark_as_bad(&header.hash());
+			let closed_block = self.check_and_close_block(&block);
+			if let Err(_) = closed_block {
+				bad_blocks.insert(header.hash());
 				break;
 			}

-			good_blocks.push(header.hash().clone());
+			// Insert block
+			let closed_block = closed_block.unwrap();
+			self.chain.write().unwrap().insert_block(&block.bytes, closed_block.block().receipts().clone());
+			good_blocks.push(header.hash());
+
+			let ancient = if header.number() >= HISTORY {
+				let n = header.number() - HISTORY;
+				let chain = self.chain.read().unwrap();
+				Some((n, chain.block_hash(n).unwrap()))
+			} else {
+				None
+			};
+
+			// Commit results
+			closed_block.drain()
+				.commit(header.number(), &header.hash(), ancient)
+				.expect("State DB commit failed.");

-			self.chain.write().unwrap().insert_block(&block.bytes, result.block().receipts().clone()); //TODO: err here?
-			let ancient = if header.number() >= HISTORY { Some(header.number() - HISTORY) } else { None };
-			match result.drain().commit(header.number(), &header.hash(), ancient.map(|n|(n, self.chain.read().unwrap().block_hash(n).unwrap()))) {
-				Ok(_) => (),
-				Err(e) => {
-					warn!(target: "client", "State DB commit failed: {:?}", e);
-					break;
-				}
-			}
 			self.report.write().unwrap().accrue_block(&block);
 			trace!(target: "client", "Imported #{} ({})", header.number(), header.hash());
-			ret += 1;
 		}
-		self.block_queue.write().unwrap().mark_as_good(&good_blocks);
-		if !good_blocks.is_empty() && self.block_queue.read().unwrap().queue_info().is_empty() {
-			io.send(NetworkIoMessage::User(SyncMessage::BlockVerified)).unwrap();
+
+		let imported = good_blocks.len();
+		let bad_blocks = bad_blocks.into_iter().collect::<Vec<H256>>();
+
+		{
+			let mut block_queue = self.block_queue.write().unwrap();
+			block_queue.mark_as_bad(&bad_blocks);
+			block_queue.mark_as_good(&good_blocks);
 		}
-		ret
+
+		{
+			let block_queue = self.block_queue.read().unwrap();
+			if !good_blocks.is_empty() && block_queue.queue_info().is_empty() {
+				io.send(NetworkIoMessage::User(SyncMessage::NewChainBlocks {
+					good: good_blocks,
+					bad: bad_blocks,
+				})).unwrap();
+			}
+		}
+
+		imported
 	}

 	/// Get a copy of the best block's state.
@ -389,7 +431,7 @@ impl BlockChainClient for Client {
 			None => BlockStatus::Unknown
 		}
 	}
-	
+
 	fn block_total_difficulty(&self, id: BlockId) -> Option<U256> {
 		let chain = self.chain.read().unwrap();
 		Self::block_hash(&chain, id).and_then(|hash| chain.block_details(&hash)).map(|d| d.total_difficulty)
@ -499,7 +541,7 @@ impl BlockChainClient for Client {
 							.collect::<Vec<LocalizedLogEntry>>()
 					})
 					.collect::<Vec<LocalizedLogEntry>>()
-					
+
 			})
 			.collect()
 	}
--- a/ethcore/src/ethereum/ethash.rs
+++ b/ethcore/src/ethereum/ethash.rs
@ -282,7 +282,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(&mut db);
 		let last_hashes = vec![genesis_header.hash()];
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, &last_hashes, Address::zero(), vec![]);
+		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), vec![]);
 		let b = b.close();
 		assert_eq!(b.state().balance(&Address::zero()), U256::from_str("4563918244f40000").unwrap());
 	}
@ -295,7 +295,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(&mut db);
 		let last_hashes = vec![genesis_header.hash()];
-		let mut b = OpenBlock::new(engine.deref(), db, &genesis_header, &last_hashes, Address::zero(), vec![]);
+		let mut b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), vec![]);
 		let mut uncle = Header::new();
 		let uncle_author = address_from_hex("ef2d6d194084c2de36e0dabfce45d046b37d1106");
 		uncle.author = uncle_author.clone();
--- a/ethcore/src/lib.rs
+++ b/ethcore/src/lib.rs
@ -40,23 +40,17 @@
 //! - Ubuntu 14.04 and later:
 //!
 //!   ```bash
-//!   # install rocksdb
-//!   add-apt-repository "deb http://ppa.launchpad.net/giskou/librocksdb/ubuntu trusty main"
-//!   apt-get update
-//!   apt-get install -y --force-yes librocksdb
 //!
 //!   # install multirust
 //!   curl -sf https://raw.githubusercontent.com/brson/multirust/master/blastoff.sh | sh -s -- --yes
 //!
-//!   # install nightly and make it default
-//!   multirust update nightly && multirust default nightly
-//!
 //!   # export rust LIBRARY_PATH
 //!   export LIBRARY_PATH=/usr/local/lib
 //!
 //!   # download and build parity
 //!   git clone https://github.com/ethcore/parity
 //!   cd parity
+//!   multirust override beta
 //!   cargo build --release
 //!   ```
 //!
@ -65,18 +59,15 @@
 //!   ```bash
 //!   # install rocksdb && multirust
 //!   brew update
-//!   brew install rocksdb
 //!   brew install multirust
 //!
-//!   # install nightly and make it default
-//!   multirust update nightly && multirust default nightly
-//!
 //!   # export rust LIBRARY_PATH
 //!   export LIBRARY_PATH=/usr/local/lib
 //!
 //!   # download and build parity
 //!   git clone https://github.com/ethcore/parity
 //!   cd parity
+//!   multirust override beta
 //!   cargo build --release
 //!   ```

--- a/ethcore/src/service.rs
+++ b/ethcore/src/service.rs
@ -26,7 +26,12 @@ use client::Client;
 #[derive(Clone)]
 pub enum SyncMessage {
 	/// New block has been imported into the blockchain
-	NewChainBlock(Bytes), //TODO: use Cow
+	NewChainBlocks {
+		/// Hashes of blocks imported to blockchain
+		good: Vec<H256>,
+		/// Hashes of blocks not imported to blockchain
+		bad: Vec<H256>,
+	},
 	/// A block is ready
 	BlockVerified,
 }
--- a/install-deps.sh
+++ b/install-deps.sh
@ -342,8 +342,6 @@ function run_installer()
 		exe brew update
 		echo

-		info "Installing rocksdb"
-		exe brew install rocksdb
 		info "Installing multirust"
 		exe brew install multirust
 		sudo multirust default beta
@ -391,7 +389,6 @@ function run_installer()
 		linux_version

 		find_multirust
-		find_rocksdb

 		find_curl
 		find_git
@ -402,21 +399,6 @@ function run_installer()
 		find_sudo
 	}

-	function find_rocksdb()
-	{
-		depCount=$((depCount+1))
-		if [[ $(ldconfig -v 2>/dev/null | grep rocksdb | wc -l) == 1 ]]; then
-			depFound=$((depFound+1))
-			check "apt-get"
-			isRocksDB=true
-			INSTALL_FILES+="${blue}${dim}==> librocksdb:${reset}$n"
-		else
-			uncheck "librocksdb is missing"
-			isRocksDB=false
-			INSTALL_FILES+="${blue}${dim}==> librocksdb:${reset}$n"
-		fi
-	}
-
 	function find_multirust()
 	{
 		depCount=$((depCount+2))
@ -562,34 +544,6 @@ function run_installer()
 		fi
 	}

-	function ubuntu_rocksdb_installer()
-	{
-		sudo apt-get update -qq
-		sudo apt-get install -qq -y software-properties-common
-		sudo apt-add-repository -y ppa:ethcore/ethcore
-		sudo apt-get -f -y install
-		sudo apt-get update -qq
-		sudo apt-get install -qq -y librocksdb-dev librocksdb
-	}
-
-	function linux_rocksdb_installer()
-	{
-		if [[ $isUbuntu == true ]]; then
-			ubuntu_rocksdb_installer
-		else
-			oldpwd=`pwd`
-			cd /tmp
-			exe git clone --branch v4.2 --depth=1 https://github.com/facebook/rocksdb.git
-			cd rocksdb
-			exe make shared_lib
-			sudo cp -a librocksdb.so* /usr/lib
-			sudo ldconfig
-			cd /tmp
-			rm -rf /tmp/rocksdb
-			cd $oldpwd
-		fi
-	}
-
 	function linux_installer()
 	{
 		if [[ $isGCC == false || $isGit == false || $isMake == false || $isCurl == false ]]; then
@ -610,12 +564,6 @@ function run_installer()
 			echo
 		fi

-		if [[ $isRocksDB == false ]]; then
-			info "Installing rocksdb..."
-			linux_rocksdb_installer
-			echo
-		fi
-
 		if [[ $isMultirust == false ]]; then
 			info "Installing multirust..."
 			if [[ $isSudo == false ]]; then
@ -655,10 +603,9 @@ function run_installer()
 			find_git
 			find_make
 			find_gcc
-			find_rocksdb
 			find_multirust

-			if [[ $isCurl == false || $isGit == false || $isMake == false || $isGCC == false || $isRocksDB == false || $isMultirustBeta == false ]]; then
+			if [[ $isCurl == false || $isGit == false || $isMake == false || $isGCC == false || $isMultirustBeta == false ]]; then
 				abort_install
 			fi
 		fi
--- a/install-parity.sh
+++ b/install-parity.sh
@ -236,14 +236,29 @@ function run_installer()
 	{
 		linux_version

-		find_rocksdb
-
 		find_curl

 		find_apt
 		find_sudo
 	}

+	function find_git()
+	{
+		depCount=$((depCount+1))
+		GIT_PATH=`which git 2>/dev/null`
+
+		if [[ -f $GIT_PATH ]]
+		then
+			depFound=$((depFound+1))
+			check "git"
+			isGit=true
+		else
+			uncheck "git is missing"
+			isGit=false
+			INSTALL_FILES+="${blue}${dim}==> git:${reset}${n}"
+		fi
+	}
+
 	function find_brew()
 	{
 		BREW_PATH=`which brew 2>/dev/null`
@ -333,20 +348,6 @@ function run_installer()
 		fi
 	}

-	function find_rocksdb()
-	{
-		depCount=$((depCount+1))
-		if [[ $(ldconfig -v 2>/dev/null | grep rocksdb | wc -l) == 1 ]]; then
-			depFound=$((depFound+1))
-			check "librocksdb"
-			isRocksDB=true
-		else
-			uncheck "librocksdb is missing"
-			isRocksDB=false
-			INSTALL_FILES+="${blue}${dim}==>${reset}\tlibrocksdb${n}"
-		fi
-	}
-
 	function find_apt()
 	{
 		depCount=$((depCount+1))
@ -386,10 +387,9 @@ function run_installer()
 		info "Verifying installation"

 		if [[ $OS_TYPE == "linux" ]]; then
-			find_rocksdb
 			find_apt

-			if [[ $isRocksDB == false || $isApt == false ]]; then
+			if [[ $isApt == false ]]; then
 				abortInstall
 			fi
 		fi
@ -397,23 +397,11 @@ function run_installer()
 	
 	function linux_deps_installer()
 	{
-		if [[ $isRocksDB == false || $isCurl == false ]]; then
+		if [[ $isCurl == false ]]; then
 			info "Preparing apt..."
 			sudo apt-get update -qq
 			echo
 		fi
-		
-		if [[ $isRocksDB == false ]]; then
-			info "Installing rocksdb..."
-
-			sudo apt-get install -qq -y software-properties-common
-			sudo apt-add-repository -y ppa:ethcore/ethcore
-			sudo apt-get -f -y install
-			sudo apt-get update -qq
-			sudo apt-get install -qq -y librocksdb
-
-			echo
-		fi

 		if [[ $isCurl == false ]]; then
 			info "Installing curl..."
--- a/parity/main.rs
+++ b/parity/main.rs
@ -71,9 +71,9 @@ Options:
  --listen-address URL     Specify the IP/port on which to listen for peers [default: 0.0.0.0:30304].
  --public-address URL     Specify the IP/port on which peers may connect.
  --address URL            Equivalent to --listen-address URL --public-address URL.
-  --peers NUM              Try to manintain that many peers [default: 25].
+  --peers NUM              Try to maintain that many peers [default: 25].
  --no-discovery           Disable new peer discovery.
-  --upnp                   Use UPnP to try to figure out the correct network settings.
+  --no-upnp                Disable trying to figure out the correct public adderss over UPnP.
  --node-key KEY           Specify node secret key, either as 64-character hex string or input to SHA3 operation.

  --cache-pref-size BYTES  Specify the prefered size of the blockchain cache in bytes [default: 16384].
@ -102,7 +102,7 @@ struct Args {
 	flag_address: Option<String>,
 	flag_peers: u32,
 	flag_no_discovery: bool,
-	flag_upnp: bool,
+	flag_no_upnp: bool,
 	flag_node_key: Option<String>,
 	flag_cache_pref_size: usize,
 	flag_cache_max_size: usize,
@ -246,7 +246,7 @@ impl Configuration {

 	fn net_settings(&self, spec: &Spec) -> NetworkConfiguration {
 		let mut ret = NetworkConfiguration::new();
-		ret.nat_enabled = self.args.flag_upnp;
+		ret.nat_enabled = !self.args.flag_no_upnp;
 		ret.boot_nodes = self.init_nodes(spec);
 		let (listen, public) = self.net_addresses();
 		ret.listen_address = listen;
--- a/util/Cargo.toml
+++ b/util/Cargo.toml
@ -39,6 +39,7 @@ target_info = "0.1"
 [features]
 default = []
 dev = ["clippy"]
+x64asm = []

 [build-dependencies]
 vergen = "*"
--- a/util/benches/bigint.rs
+++ b/util/benches/bigint.rs
@ -0,0 +1,84 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! benchmarking for rlp
+//! should be started with:
+//! ```bash
+//! multirust run nightly cargo bench
+//! ```
+
+#![feature(test)]
+#![feature(asm)]
+
+extern crate test;
+extern crate ethcore_util;
+extern crate rand;
+
+use test::{Bencher, black_box};
+use ethcore_util::uint::*;
+
+#[bench]
+fn u256_add(b: &mut Bencher) {
+	b.iter(|| {
+		let n = black_box(10000);
+		(0..n).fold(U256([rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>()]), |old, new| { old.overflowing_add(U256::from(new)).0 })
+	});
+}
+
+#[bench]
+fn u256_sub(b: &mut Bencher) {
+	b.iter(|| {
+		let n = black_box(10000);
+		(0..n).fold(U256([rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>()]), |old, new| { old.overflowing_sub(U256::from(new)).0 })
+	});
+}
+
+#[bench]
+fn u512_sub(b: &mut Bencher) {
+	b.iter(|| {
+		let n = black_box(10000);
+		(0..n).fold(U512([rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(),
+				rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>()]),
+			|old, new| { old.overflowing_sub(U512([0, 0, 0, 0, 0, 0, 0, new])).0 })
+	});
+}
+
+#[bench]
+fn u512_add(b: &mut Bencher) {
+	b.iter(|| {
+		let n = black_box(10000);
+		(0..n).fold(U512([0, 0, 0, 0, 0, 0, 0, 0]),
+			|old, new| { old.overflowing_add(U512([new, new, new, new, new, new, new, new])).0 })
+	});
+}
+
+#[bench]
+fn u256_mul(b: &mut Bencher) {
+	b.iter(|| {
+		let n = black_box(10000);
+		(0..n).fold(U256([rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>(), rand::random::<u64>()]), |old, new| { old.overflowing_mul(U256::from(new)).0 })
+	});
+}
+
+
+#[bench]
+fn u128_mul(b: &mut Bencher) {
+	b.iter(|| {
+		let n = black_box(10000);
+		(0..n).fold(U128([12345u64, 0u64]), |old, new| { old.overflowing_mul(U128::from(new)).0 })
+	});
+}
+
--- a/util/res/geth_keystore/UTC--2016-02-17T09-20-45.721400158Z--3f49624084b67849c7b4e805c5988c21a430f9d9
+++ b/util/res/geth_keystore/UTC--2016-02-17T09-20-45.721400158Z--3f49624084b67849c7b4e805c5988c21a430f9d9
@ -0,0 +1,21 @@
+{
+	"address": "3f49624084b67849c7b4e805c5988c21a430f9d9",
+	"Crypto": {
+		"cipher": "aes-128-ctr",
+		"ciphertext": "9f27e3dd4fc73e7103ed61e5493662189a3eb52223ae49e3d1deacc04c889eae",
+		"cipherparams": {
+			"iv": "457494bf05f2618c397dc74dbb5181c0"
+		},
+		"kdf": "scrypt",
+		"kdfparams": {
+			"dklen": 32,
+			"n": 262144,
+			"p": 1,
+			"r": 8,
+			"salt": "db14edb18c41ee7f5ec4397df89c3a2ae4d0af60884c52bb54ce490574f8df33"
+		},
+		"mac": "572d24532438d31fdf513c744a3ff26c933ffda5744ee42bc71661cbe3f2112e"
+	},
+	"id": "62a0ad73-556d-496a-8e1c-0783d30d3ace",
+	"version": 3
+}
--- a/util/res/geth_keystore/UTC--2016-02-20T09-33-03.984382741Z--5ba4dcf897e97c2bdf8315b9ef26c13c085988cf
+++ b/util/res/geth_keystore/UTC--2016-02-20T09-33-03.984382741Z--5ba4dcf897e97c2bdf8315b9ef26c13c085988cf
@ -0,0 +1,21 @@
+{
+	"address": "5ba4dcf897e97c2bdf8315b9ef26c13c085988cf",
+	"Crypto": {
+		"cipher": "aes-128-ctr",
+		"ciphertext": "d4a08ec930163778273920f6ad1d49b71836337be6fd9863993ac700a612fddd",
+		"cipherparams": {
+			"iv": "89ce5ec129fc27cd5bcbeb8c92bdad50"
+		},
+		"kdf": "scrypt",
+		"kdfparams": {
+			"dklen": 32,
+			"n": 262144,
+			"p": 1,
+			"r": 8,
+			"salt": "612ab108dc37e69ee8af37a7b24bf7f2234086d7bbf945bacdeccce331f7f84a"
+		},
+		"mac": "4152caa7444e06784223d735cea80cd2690b4c587ad8db3d5529442227b25695"
+	},
+	"id": "35086353-fb12-4029-b56b-033cd61ce35b",
+	"version": 3
+}
--- a/util/src/hash.rs
+++ b/util/src/hash.rs
@ -235,7 +235,7 @@ macro_rules! impl_hash {
 		}

 		impl serde::Serialize for $from {
-			fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> 
+			fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
 			where S: serde::Serializer {
 				let mut hex = "0x".to_owned();
 				hex.push_str(self.to_hex().as_ref());
@ -250,7 +250,7 @@ macro_rules! impl_hash {

 				impl serde::de::Visitor for HashVisitor {
 					type Value = $from;
-					
+
 					fn visit_str<E>(&mut self, value: &str) -> Result<Self::Value, E> where E: serde::Error {
 						// 0x + len
 						if value.len() != 2 + $size * 2 {
@ -719,4 +719,3 @@ mod tests {
 		assert_eq!(r, u);
 	}
 }
-
--- a/util/src/keys/directory.rs
+++ b/util/src/keys/directory.rs
@ -333,7 +333,9 @@ pub struct KeyFileContent {
 	/// Holds cypher and decrypt function settings.
 	pub crypto: KeyFileCrypto,
 	/// The identifier.
-	pub id: Uuid
+	pub id: Uuid,
+	/// Account (if present)
+	pub account: Option<Address>,
 }

 #[derive(Debug)]
@ -374,7 +376,19 @@ impl KeyFileContent {
 		KeyFileContent {
 			id: new_uuid(),
 			version: KeyFileVersion::V3(3),
-			crypto: crypto
+			crypto: crypto,
+			account: None
+		}
+	}
+
+	/// Loads key from valid json, returns error and records warning if key is mallformed
+	pub fn load(json: &Json) -> Result<KeyFileContent, ()> {
+		match Self::from_json(json) {
+			Ok(key_file) => Ok(key_file),
+			Err(e) => {
+				warn!(target: "sstore", "Error parsing json for key: {:?}", e);
+				Err(())
+			}
 		}
 	}

@ -407,6 +421,9 @@ impl KeyFileContent {
 			Ok(id) => id
 		};

+		let account = as_object.get("address").and_then(|json| json.as_string()).and_then(
+			|account_text| match Address::from_str(account_text) { Ok(account) => Some(account), Err(_) => None });
+
 		let crypto = match as_object.get("crypto") {
 			None => { return Err(KeyFileParseError::NoCryptoSection); }
 			Some(crypto_json) => match KeyFileCrypto::from_json(crypto_json) {
@ -418,7 +435,8 @@ impl KeyFileContent {
 		Ok(KeyFileContent {
 			version: version,
 			id: id.clone(),
-			crypto: crypto
+			crypto: crypto,
+			account: account
 		})
 	}

@ -427,6 +445,7 @@ impl KeyFileContent {
 		map.insert("id".to_owned(), Json::String(uuid_to_string(&self.id)));
 		map.insert("version".to_owned(), Json::U64(CURRENT_DECLARED_VERSION));
 		map.insert("crypto".to_owned(), self.crypto.to_json());
+		if let Some(ref address) = self.account { map.insert("address".to_owned(), Json::String(format!("{:?}", address))); }
 		Json::Object(map)
 	}
 }
@ -599,6 +618,8 @@ impl KeyDirectory {
 			Err(_) => Err(KeyFileLoadError::ParseError(KeyFileParseError::InvalidJson))
 		}
 	}
+
+
 }


@ -653,7 +674,7 @@ mod file_tests {
 	}

 	#[test]
-	fn can_read_scrypt_krf() {
+	fn can_read_scrypt_kdf() {
 		let json = Json::from_str(
 			r#"
 				{
@ -689,6 +710,47 @@ mod file_tests {
 		}
 	}

+	#[test]
+	fn can_read_scrypt_kdf_params() {
+		let json = Json::from_str(
+			r#"
+				{
+					"crypto" : {
+						"cipher" : "aes-128-ctr",
+						"cipherparams" : {
+							"iv" : "83dbcc02d8ccb40e466191a123791e0e"
+						},
+						"ciphertext" : "d172bf743a674da9cdad04534d56926ef8358534d458fffccd4e6ad2fbde479c",
+						"kdf" : "scrypt",
+						"kdfparams" : {
+							"dklen" : 32,
+							"n" : 262144,
+							"r" : 1,
+							"p" : 8,
+							"salt" : "ab0c7876052600dd703518d6fc3fe8984592145b591fc8fb5c6d43190334ba19"
+						},
+						"mac" : "2103ac29920d71da29f15d75b4a16dbe95cfd7ff8faea1056c33131d846e3097"
+					},
+					"id" : "3198bc9c-6672-5ab3-d995-4942343ae5b6",
+					"version" : 3
+				}
+			"#).unwrap();
+
+		match KeyFileContent::from_json(&json) {
+			Ok(key_file) => {
+				match key_file.crypto.kdf {
+					KeyFileKdf::Scrypt(scrypt_params) => {
+						assert_eq!(262144, scrypt_params.n);
+						assert_eq!(1, scrypt_params.r);
+						assert_eq!(8, scrypt_params.p);
+					},
+					_ => { panic!("expected kdf params of crypto to be of scrypt type" ); }
+				}
+			},
+			Err(e) => panic!("Error parsing valid file: {:?}", e)
+		}
+	}
+
 	#[test]
 	fn can_return_error_no_id() {
 		let json = Json::from_str(
@ -844,7 +906,7 @@ mod file_tests {
 				panic!("Should be error of no identifier, got ok");
 			},
 			Err(KeyFileParseError::Crypto(CryptoParseError::Scrypt(_))) => { },
-			Err(other_error) => { panic!("should be error of no identifier, got {:?}", other_error); }
+			Err(other_error) => { panic!("should be scrypt parse error, got {:?}", other_error); }
 		}
 	}

--- a/util/src/keys/geth_import.rs
+++ b/util/src/keys/geth_import.rs
@ -0,0 +1,165 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Geth keys import/export tool
+
+use common::*;
+use keys::store::SecretStore;
+use keys::directory::KeyFileContent;
+
+/// Enumerates all geth keys in the directory and returns collection of tuples `(accountId, filename)`
+pub fn enumerate_geth_keys(path: &Path) -> Result<Vec<(Address, String)>, io::Error> {
+	let mut entries = Vec::new();
+	for entry in try!(fs::read_dir(path)) {
+		let entry = try!(entry);
+		if !try!(fs::metadata(entry.path())).is_dir() {
+			match entry.file_name().to_str() {
+				Some(name) => {
+					let parts: Vec<&str> = name.split("--").collect();
+					if parts.len() != 3 { continue; }
+					match Address::from_str(parts[2]) {
+						Ok(account_id) => { entries.push((account_id, name.to_owned())); }
+						Err(e) => { panic!("error: {:?}", e); }
+					}
+				},
+				None => { continue; }
+			};
+		}
+	}
+	Ok(entries)
+}
+
+/// Geth import error
+#[derive(Debug)]
+pub enum ImportError {
+	/// Io error reading geth file
+	IoError(io::Error),
+	/// format error
+	FormatError,
+}
+
+impl From<io::Error> for ImportError {
+	fn from (err: io::Error) -> ImportError {
+		ImportError::IoError(err)
+	}
+}
+
+/// Imports one geth key to the store
+pub fn import_geth_key(secret_store: &mut SecretStore, geth_keyfile_path: &Path) -> Result<(), ImportError> {
+	let mut file = try!(fs::File::open(geth_keyfile_path));
+	let mut buf = String::new();
+	try!(file.read_to_string(&mut buf));
+
+	let mut json_result = Json::from_str(&buf);
+	let mut json = match json_result {
+		Ok(ref mut parsed_json) => try!(parsed_json.as_object_mut().ok_or(ImportError::FormatError)),
+		Err(_) => { return Err(ImportError::FormatError); }
+	};
+	let crypto_object = try!(json.get("Crypto").and_then(|crypto| crypto.as_object()).ok_or(ImportError::FormatError)).clone();
+	json.insert("crypto".to_owned(), Json::Object(crypto_object));
+	json.remove("Crypto");
+	match KeyFileContent::load(&Json::Object(json.clone())) {
+		Ok(key_file) => try!(secret_store.import_key(key_file)),
+		Err(_) => { return Err(ImportError::FormatError); }
+	};
+	Ok(())
+}
+
+/// Imports all geth keys in the directory
+pub fn import_geth_keys(secret_store: &mut SecretStore, geth_keyfiles_directory: &Path) -> Result<(), ImportError> {
+	use std::path::PathBuf;
+	let geth_files = try!(enumerate_geth_keys(geth_keyfiles_directory));
+	for &(ref address, ref file_path) in geth_files.iter() {
+		let mut path = PathBuf::new();
+		path.push(geth_keyfiles_directory);
+		path.push(file_path);
+		if let Err(e) = import_geth_key(secret_store, Path::new(&path)) {
+			warn!("Skipped geth address {}, error importing: {:?}", address, e)
+		}
+	}
+	Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use common::*;
+	use keys::store::SecretStore;
+
+
+	#[test]
+	fn can_enumerate() {
+		let keys = enumerate_geth_keys(Path::new("res/geth_keystore")).unwrap();
+		assert_eq!(2, keys.len());
+	}
+
+	#[test]
+	fn can_import() {
+		let temp = ::devtools::RandomTempPath::create_dir();
+		let mut secret_store = SecretStore::new_in(temp.as_path());
+		import_geth_key(&mut secret_store, Path::new("res/geth_keystore/UTC--2016-02-17T09-20-45.721400158Z--3f49624084b67849c7b4e805c5988c21a430f9d9")).unwrap();
+		let key = secret_store.account(&Address::from_str("3f49624084b67849c7b4e805c5988c21a430f9d9").unwrap());
+		assert!(key.is_some());
+	}
+
+	#[test]
+	fn can_import_directory() {
+		let temp = ::devtools::RandomTempPath::create_dir();
+		let mut secret_store = SecretStore::new_in(temp.as_path());
+		import_geth_keys(&mut secret_store, Path::new("res/geth_keystore")).unwrap();
+
+		let key = secret_store.account(&Address::from_str("3f49624084b67849c7b4e805c5988c21a430f9d9").unwrap());
+		assert!(key.is_some());
+
+		let key = secret_store.account(&Address::from_str("5ba4dcf897e97c2bdf8315b9ef26c13c085988cf").unwrap());
+		assert!(key.is_some());
+	}
+
+	#[test]
+	fn imports_as_scrypt_keys() {
+		use keys::directory::{KeyDirectory, KeyFileKdf};
+		let temp = ::devtools::RandomTempPath::create_dir();
+		{
+			let mut secret_store = SecretStore::new_in(temp.as_path());
+			import_geth_keys(&mut secret_store, Path::new("res/geth_keystore")).unwrap();
+		}
+
+		let key_directory = KeyDirectory::new(&temp.as_path());
+		let key_file = key_directory.get(&H128::from_str("62a0ad73556d496a8e1c0783d30d3ace").unwrap()).unwrap();
+
+		match key_file.crypto.kdf {
+			KeyFileKdf::Scrypt(scrypt_params) => {
+				assert_eq!(262144, scrypt_params.n);
+				assert_eq!(8, scrypt_params.r);
+				assert_eq!(1, scrypt_params.p);
+			},
+			_ => { panic!("expected kdf params of crypto to be of scrypt type" ); }
+		}
+	}
+
+	#[test]
+	fn can_decrypt_with_imported() {
+		use keys::store::EncryptedHashMap;
+
+		let temp = ::devtools::RandomTempPath::create_dir();
+		let mut secret_store = SecretStore::new_in(temp.as_path());
+		import_geth_keys(&mut secret_store, Path::new("res/geth_keystore")).unwrap();
+
+		let val = secret_store.get::<Bytes>(&H128::from_str("62a0ad73556d496a8e1c0783d30d3ace").unwrap(), "123");
+		assert!(val.is_ok());
+		assert_eq!(32, val.unwrap().len());
+	}
+}
--- a/util/src/keys/mod.rs
+++ b/util/src/keys/mod.rs
@ -18,3 +18,4 @@

 pub mod directory;
 pub mod store;
+mod geth_import;
--- a/util/src/keys/store.rs
+++ b/util/src/keys/store.rs
@ -19,11 +19,12 @@
 use keys::directory::*;
 use common::*;
 use rcrypto::pbkdf2::*;
+use rcrypto::scrypt::*;
 use rcrypto::hmac::*;
 use crypto;

 const KEY_LENGTH: u32 = 32;
-const KEY_ITERATIONS: u32 = 4096;
+const KEY_ITERATIONS: u32 = 10240;
 const KEY_LENGTH_AES: u32 = KEY_LENGTH/2;

 const KEY_LENGTH_USIZE: usize = KEY_LENGTH as usize;
@ -60,15 +61,62 @@ pub struct SecretStore {
 }

 impl SecretStore {
-	/// new instance of Secret Store
+	/// new instance of Secret Store in default home directory
 	pub fn new() -> SecretStore {
 		let mut path = ::std::env::home_dir().expect("Failed to get home dir");
-		path.push(".keys");
+		path.push(".parity");
+		path.push("keys");
+		Self::new_in(&path)
+	}
+
+	/// new instance of Secret Store in specific directory
+	pub fn new_in(path: &Path) -> SecretStore {
 		SecretStore {
-			directory: KeyDirectory::new(&path)
+			directory: KeyDirectory::new(path)
 		}
 	}

+	/// trys to import keys in the known locations
+	pub fn try_import_existing(&mut self) {
+		use std::path::PathBuf;
+		use keys::geth_import;
+
+		let mut import_path = PathBuf::new();
+		import_path.push(::std::env::home_dir().expect("Failed to get home dir"));
+		import_path.push(".ethereum");
+		import_path.push("keystore");
+		if let Err(e) = geth_import::import_geth_keys(self, &import_path) {
+			warn!(target: "sstore", "Error retrieving geth keys: {:?}", e)
+		}
+	}
+
+	/// Lists all accounts and corresponding key ids
+	pub fn accounts(&self) -> Result<Vec<(Address, H128)>, ::std::io::Error> {
+		let accounts = try!(self.directory.list()).iter().map(|key_id| self.directory.get(key_id))
+			.filter(|key| key.is_some())
+			.map(|key| { let some_key = key.unwrap(); (some_key.account, some_key.id) })
+			.filter(|&(ref account, _)| account.is_some())
+			.map(|(account, id)| (account.unwrap(), id))
+			.collect::<Vec<(Address, H128)>>();
+		Ok(accounts)
+	}
+
+	/// Resolves key_id by account address
+	pub fn account(&self, account: &Address) -> Option<H128> {
+		let mut accounts = match self.accounts() {
+			Ok(accounts) => accounts,
+			Err(e) => { warn!(target: "sstore", "Failed to load accounts: {}", e); return None; }
+		};
+		accounts.retain(|&(ref store_account, _)| account == store_account);
+		accounts.first().and_then(|&(_, ref key_id)| Some(key_id.clone()))
+	}
+
+	/// Imports pregenerated key, returns error if not saved correctly
+	pub fn import_key(&mut self, key_file: KeyFileContent) -> Result<(), ::std::io::Error> {
+		try!(self.directory.save(key_file));
+		Ok(())
+	}
+
 	#[cfg(test)]
 	fn new_test(path: &::devtools::RandomTempPath) -> SecretStore {
 		SecretStore {
@ -90,6 +138,15 @@ fn derive_key(password: &str, salt: &H256) -> (Bytes, Bytes) {
 	derive_key_iterations(password, salt, KEY_ITERATIONS)
 }

+fn derive_key_scrypt(password: &str, salt: &H256, n: u32, p: u32, r: u32) -> (Bytes, Bytes) {
+	let mut derived_key = vec![0u8; KEY_LENGTH_USIZE];
+	let scrypt_params = ScryptParams::new(n.trailing_zeros() as u8, r, p);
+	scrypt(password.as_bytes(), &salt.as_slice(), &scrypt_params, &mut derived_key);
+	let derived_right_bits = &derived_key[0..KEY_LENGTH_AES_USIZE];
+	let derived_left_bits = &derived_key[KEY_LENGTH_AES_USIZE..KEY_LENGTH_USIZE];
+	(derived_right_bits.to_vec(), derived_left_bits.to_vec())
+}
+
 fn derive_mac(derived_left_bits: &[u8], cipher_text: &[u8]) -> Bytes {
 	let mut mac = vec![0u8; KEY_LENGTH_AES_USIZE + cipher_text.len()];
 	mac[0..KEY_LENGTH_AES_USIZE].clone_from_slice(derived_left_bits);
@ -101,24 +158,22 @@ impl EncryptedHashMap<H128> for SecretStore {
 	fn get<Value: FromRawBytes + BytesConvertable>(&self, key: &H128, password: &str) -> Result<Value, EncryptedHashMapError> {
 		match self.directory.get(key) {
 			Some(key_file) => {
-				let decrypted_bytes = match key_file.crypto.kdf {
-					KeyFileKdf::Pbkdf2(ref params) => {
-						let (derived_left_bits, derived_right_bits) = derive_key_iterations(password, &params.salt, params.c);
-						if derive_mac(&derived_right_bits, &key_file.crypto.cipher_text)
-							.sha3() != key_file.crypto.mac { return Err(EncryptedHashMapError::InvalidPassword); }
-
-						let mut val = vec![0u8; key_file.crypto.cipher_text.len()];
-						match key_file.crypto.cipher_type {
-							CryptoCipherType::Aes128Ctr(ref iv) => {
-								crypto::aes::decrypt(&derived_left_bits, &iv.as_slice(), &key_file.crypto.cipher_text, &mut val);
-							}
-						}
-						val
-					}
-					_ => { unimplemented!(); }
+				let (derived_left_bits, derived_right_bits) = match key_file.crypto.kdf {
+					KeyFileKdf::Pbkdf2(ref params) => derive_key_iterations(password, &params.salt, params.c),
+					KeyFileKdf::Scrypt(ref params) => derive_key_scrypt(password, &params.salt, params.n, params.p, params.r)
 				};

-				match Value::from_bytes(&decrypted_bytes) {
+				if derive_mac(&derived_right_bits, &key_file.crypto.cipher_text)
+					.sha3() != key_file.crypto.mac { return Err(EncryptedHashMapError::InvalidPassword); }
+
+				let mut val = vec![0u8; key_file.crypto.cipher_text.len()];
+				match key_file.crypto.cipher_type {
+					CryptoCipherType::Aes128Ctr(ref iv) => {
+						crypto::aes::decrypt(&derived_left_bits, &iv.as_slice(), &key_file.crypto.cipher_text, &mut val);
+					}
+				};
+
+				match Value::from_bytes(&val) {
 					Ok(value) => Ok(value),
 					Err(bytes_error) => Err(EncryptedHashMapError::InvalidValueFormat(bytes_error))
 				}
@ -259,6 +314,27 @@ mod tests {
 		result
 	}

+	fn pregenerate_accounts(temp: &RandomTempPath, count: usize) -> Vec<H128> {
+		use keys::directory::{KeyFileContent, KeyFileCrypto};
+		let mut write_sstore = SecretStore::new_test(&temp);
+		let mut result = Vec::new();
+		for i in 0..count {
+			let mut key_file =
+				KeyFileContent::new(
+					KeyFileCrypto::new_pbkdf2(
+						FromHex::from_hex("5318b4d5bcd28de64ee5559e671353e16f075ecae9f99c7a79a38af5f869aa46").unwrap(),
+						H128::from_str("6087dab2f9fdbbfaddc31a909735c1e6").unwrap(),
+						H256::from_str("ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd").unwrap(),
+						H256::from_str("517ead924a9d0dc3124507e3393d175ce3ff7c1e96529c6c555ce9e51205e9b2").unwrap(),
+						262144,
+						32));
+			key_file.account = Some(x!(i as u64));
+			result.push(key_file.id.clone());
+			write_sstore.import_key(key_file).unwrap();
+		}
+		result
+	}
+
 	#[test]
 	fn can_get() {
 		let temp = RandomTempPath::create_dir();
@ -293,5 +369,35 @@ mod tests {
 		assert_eq!(4, sstore.directory.list().unwrap().len())
 	}

+	#[test]
+	fn can_import_account() {
+		use keys::directory::{KeyFileContent, KeyFileCrypto};
+		let temp = RandomTempPath::create_dir();
+		let mut key_file =
+			KeyFileContent::new(
+				KeyFileCrypto::new_pbkdf2(
+					FromHex::from_hex("5318b4d5bcd28de64ee5559e671353e16f075ecae9f99c7a79a38af5f869aa46").unwrap(),
+					H128::from_str("6087dab2f9fdbbfaddc31a909735c1e6").unwrap(),
+					H256::from_str("ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd").unwrap(),
+					H256::from_str("517ead924a9d0dc3124507e3393d175ce3ff7c1e96529c6c555ce9e51205e9b2").unwrap(),
+					262144,
+					32));
+		key_file.account = Some(Address::from_str("3f49624084b67849c7b4e805c5988c21a430f9d9").unwrap());

+		let mut sstore = SecretStore::new_test(&temp);
+
+		sstore.import_key(key_file).unwrap();
+
+		assert_eq!(1, sstore.accounts().unwrap().len());
+		assert!(sstore.account(&Address::from_str("3f49624084b67849c7b4e805c5988c21a430f9d9").unwrap()).is_some());
+	}
+
+	#[test]
+	fn can_list_accounts() {
+		let temp = RandomTempPath::create_dir();
+		pregenerate_accounts(&temp, 30);
+		let sstore = SecretStore::new_test(&temp);
+		let accounts = sstore.accounts().unwrap();
+		assert_eq!(30, accounts.len());
+	}
 }
--- a/util/src/lib.rs
+++ b/util/src/lib.rs
@ -16,6 +16,7 @@

 #![warn(missing_docs)]
 #![cfg_attr(feature="dev", feature(plugin))]
+#![cfg_attr(feature="x64asm", feature(asm))]
 #![cfg_attr(feature="dev", plugin(clippy))]

 // Clippy settings
--- a/util/src/network/host.rs
+++ b/util/src/network/host.rs
@ -106,6 +106,7 @@ const IDLE: usize = LAST_HANDSHAKE + 2;
 const DISCOVERY: usize = LAST_HANDSHAKE + 3;
 const DISCOVERY_REFRESH: usize = LAST_HANDSHAKE + 4;
 const DISCOVERY_ROUND: usize = LAST_HANDSHAKE + 5;
+const INIT_PUBLIC: usize = LAST_HANDSHAKE + 6;
 const FIRST_SESSION: usize = 0;
 const LAST_SESSION: usize = FIRST_SESSION + MAX_SESSIONS - 1;
 const FIRST_HANDSHAKE: usize = LAST_SESSION + 1;
@ -261,7 +262,9 @@ pub struct HostInfo {
 	/// TCP connection port.
 	pub listen_port: u16,
 	/// Registered capabilities (handlers)
-	pub capabilities: Vec<CapabilityInfo>
+	pub capabilities: Vec<CapabilityInfo>,
+	/// Public address + discovery port
+	public_endpoint: NodeEndpoint,
 }

 impl HostInfo {
@ -294,16 +297,15 @@ struct ProtocolTimer {
 /// Root IO handler. Manages protocol handlers, IO timers and network connections.
 pub struct Host<Message> where Message: Send + Sync + Clone {
 	pub info: RwLock<HostInfo>,
-	tcp_listener: Mutex<TcpListener>,
+	tcp_listener: Mutex<Option<TcpListener>>,
 	handshakes: Arc<RwLock<Slab<SharedHandshake>>>,
 	sessions: Arc<RwLock<Slab<SharedSession>>>,
-	discovery: Option<Mutex<Discovery>>,
+	discovery: Mutex<Option<Discovery>>,
 	nodes: RwLock<NodeTable>,
 	handlers: RwLock<HashMap<ProtocolId, Arc<NetworkProtocolHandler<Message>>>>,
 	timers: RwLock<HashMap<TimerToken, ProtocolTimer>>,
 	timer_counter: RwLock<usize>,
 	stats: Arc<NetworkStats>,
-	public_endpoint: NodeEndpoint,
 	pinned_nodes: Vec<NodeId>,
 }

@ -316,27 +318,6 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 		};

 		let udp_port = config.udp_port.unwrap_or(listen_address.port());
-		let public_endpoint = match config.public_address {
-			None => {
-				let public_address = select_public_address(listen_address.port());
-				let local_endpoint = NodeEndpoint { address: public_address, udp_port: udp_port };
-				if config.nat_enabled {
-					match map_external_address(&local_endpoint) {
-						Some(endpoint) => {
-							info!("NAT Mappped to external address {}", endpoint.address);
-							endpoint
-						},
-						None => local_endpoint
-					}
-				} else {
-					local_endpoint
-				}
-			}
-			Some(addr) => NodeEndpoint { address: addr, udp_port: udp_port }
-		};
-
-		// Setup the server socket
-		let tcp_listener = TcpListener::bind(&listen_address).unwrap();
 		let keys = if let Some(ref secret) = config.use_secret {
 			KeyPair::from_secret(secret.clone()).unwrap()
 		} else {
@ -350,10 +331,8 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 			},
 			|s| KeyPair::from_secret(s).expect("Error creating node secret key"))
 		};
-		let discovery = if config.discovery_enabled && !config.pin {
-			Some(Discovery::new(&keys, listen_address.clone(), public_endpoint.clone(), DISCOVERY))
-		} else { None };
 		let path = config.config_path.clone();
+		let local_endpoint = NodeEndpoint { address: listen_address, udp_port: udp_port };
 		let mut host = Host::<Message> {
 			info: RwLock::new(HostInfo {
 				keys: keys,
@ -363,9 +342,10 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 				client_version: version(),
 				listen_port: 0,
 				capabilities: Vec::new(),
+				public_endpoint: local_endpoint, // will be replaced by public once it is resolved
 			}),
-			discovery: discovery.map(Mutex::new),
-			tcp_listener: Mutex::new(tcp_listener),
+			discovery: Mutex::new(None),
+			tcp_listener: Mutex::new(None),
 			handshakes: Arc::new(RwLock::new(Slab::new_starting_at(FIRST_HANDSHAKE, MAX_HANDSHAKES))),
 			sessions: Arc::new(RwLock::new(Slab::new_starting_at(FIRST_SESSION, MAX_SESSIONS))),
 			nodes: RwLock::new(NodeTable::new(path)),
@ -373,16 +353,12 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 			timers: RwLock::new(HashMap::new()),
 			timer_counter: RwLock::new(USER_TIMER),
 			stats: Arc::new(NetworkStats::default()),
-			public_endpoint: public_endpoint,
 			pinned_nodes: Vec::new(),
 		};
 		let port = listen_address.port();
 		host.info.write().unwrap().deref_mut().listen_port = port;

 		let boot_nodes = host.info.read().unwrap().config.boot_nodes.clone();
-		if let Some(ref mut discovery) = host.discovery {
-			discovery.lock().unwrap().init_node_list(host.nodes.read().unwrap().unordered_entries());
-		}
 		for n in boot_nodes {
 			host.add_node(&n);
 		}
@ -400,8 +376,8 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 				let entry = NodeEntry { endpoint: n.endpoint.clone(), id: n.id.clone() };
 				self.pinned_nodes.push(n.id.clone());
 				self.nodes.write().unwrap().add_node(n);
-				if let Some(ref mut discovery) = self.discovery {
-					discovery.lock().unwrap().add_node(entry);
+				if let &mut Some(ref mut discovery) = self.discovery.lock().unwrap().deref_mut() {
+					discovery.add_node(entry);
 				}
 			}
 		}
@ -412,7 +388,61 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 	}

 	pub fn client_url(&self) -> String {
-		format!("{}", Node::new(self.info.read().unwrap().id().clone(), self.public_endpoint.clone()))
+		format!("{}", Node::new(self.info.read().unwrap().id().clone(), self.info.read().unwrap().public_endpoint.clone()))
+	}
+
+	fn init_public_interface(&self, io: &IoContext<NetworkIoMessage<Message>>) {
+		io.clear_timer(INIT_PUBLIC).unwrap();
+		let mut tcp_listener = self.tcp_listener.lock().unwrap();
+		if tcp_listener.is_some() {
+			return;
+		}
+		// public_endpoint in host info contains local adderss at this point
+		let listen_address = self.info.read().unwrap().public_endpoint.address.clone();
+		let udp_port = self.info.read().unwrap().config.udp_port.unwrap_or(listen_address.port());
+		let public_endpoint = match self.info.read().unwrap().config.public_address {
+			None => {
+				let public_address = select_public_address(listen_address.port());
+				let local_endpoint = NodeEndpoint { address: public_address, udp_port: udp_port };
+				if self.info.read().unwrap().config.nat_enabled {
+					match map_external_address(&local_endpoint) {
+						Some(endpoint) => {
+							info!("NAT mappped to external address {}", endpoint.address);
+							endpoint
+						},
+						None => local_endpoint
+					}
+				} else {
+					local_endpoint
+				}
+			}
+			Some(addr) => NodeEndpoint { address: addr, udp_port: udp_port }
+		};
+		
+		// Setup the server socket
+		*tcp_listener = Some(TcpListener::bind(&listen_address).unwrap());
+		self.info.write().unwrap().public_endpoint = public_endpoint.clone();
+		io.register_stream(TCP_ACCEPT).expect("Error registering TCP listener");
+		info!("Public node URL: {}", self.client_url());
+
+		// Initialize discovery.
+		let discovery = {
+			let info = self.info.read().unwrap();
+			if info.config.discovery_enabled && !info.config.pin {
+				Some(Discovery::new(&info.keys, listen_address.clone(), public_endpoint, DISCOVERY))
+			} else { None }
+		};
+
+		if let Some(mut discovery) = discovery {
+			discovery.init_node_list(self.nodes.read().unwrap().unordered_entries());
+			for n in self.nodes.read().unwrap().unordered_entries() {
+				discovery.add_node(n.clone());
+			}
+			io.register_stream(DISCOVERY).expect("Error registering UDP listener");
+			io.register_timer(DISCOVERY_REFRESH, 7200).expect("Error registering discovery timer");
+			io.register_timer(DISCOVERY_ROUND, 300).expect("Error registering discovery timer");
+			*self.discovery.lock().unwrap().deref_mut() = Some(discovery);
+		}
 	}

 	fn maintain_network(&self, io: &IoContext<NetworkIoMessage<Message>>) {
@ -526,7 +556,7 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 	fn accept(&self, io: &IoContext<NetworkIoMessage<Message>>) {
 		trace!(target: "network", "Accepting incoming connection");
 		loop {
-			let socket = match self.tcp_listener.lock().unwrap().accept() {
+			let socket = match self.tcp_listener.lock().unwrap().as_ref().unwrap().accept() {
 				Ok(None) => break,
 				Ok(Some((sock, _addr))) => sock,
 				Err(e) => {
@ -666,8 +696,9 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 				if let Ok(address) = session.remote_addr() {
 					let entry = NodeEntry { id: session.id().clone(), endpoint: NodeEndpoint { address: address, udp_port: address.port() } };
 					self.nodes.write().unwrap().add_node(Node::new(entry.id.clone(), entry.endpoint.clone()));
-					if let Some(ref discovery) = self.discovery {
-						discovery.lock().unwrap().add_node(entry);
+					let mut discovery = self.discovery.lock().unwrap();
+					if let &mut Some(ref mut discovery) = discovery.deref_mut() {
+						discovery.add_node(entry);
 					}
 				}
 			}
@ -764,13 +795,8 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Message: Send + Sync + Clone + 'static {
 	/// Initialize networking
 	fn initialize(&self, io: &IoContext<NetworkIoMessage<Message>>) {
-		io.register_stream(TCP_ACCEPT).expect("Error registering TCP listener");
 		io.register_timer(IDLE, MAINTENANCE_TIMEOUT).expect("Error registering Network idle timer");
-		if self.discovery.is_some() {
-			io.register_stream(DISCOVERY).expect("Error registering UDP listener");
-			io.register_timer(DISCOVERY_REFRESH, 7200).expect("Error registering discovery timer");
-			io.register_timer(DISCOVERY_ROUND, 300).expect("Error registering discovery timer");
-		}
+		io.register_timer(INIT_PUBLIC, 0).expect("Error registering initialization timer");
 		self.maintain_network(io)
 	}

@ -788,7 +814,7 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 			FIRST_SESSION ... LAST_SESSION => self.session_readable(stream, io),
 			FIRST_HANDSHAKE ... LAST_HANDSHAKE => self.handshake_readable(stream, io),
 			DISCOVERY => {
-				let node_changes = { self.discovery.as_ref().unwrap().lock().unwrap().readable() };
+				let node_changes = { self.discovery.lock().unwrap().as_mut().unwrap().readable() };
 				if let Some(node_changes) = node_changes {
 					self.update_nodes(io, node_changes);
 				}
@ -804,7 +830,7 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 			FIRST_SESSION ... LAST_SESSION => self.session_writable(stream, io),
 			FIRST_HANDSHAKE ... LAST_HANDSHAKE => self.handshake_writable(stream, io),
 			DISCOVERY => {
-				self.discovery.as_ref().unwrap().lock().unwrap().writable();
+				self.discovery.lock().unwrap().as_mut().unwrap().writable();
 				io.update_registration(DISCOVERY).expect("Error updating discovery registration");
 			}
 			_ => panic!("Received unknown writable token"),
@ -814,14 +840,15 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 	fn timeout(&self, io: &IoContext<NetworkIoMessage<Message>>, token: TimerToken) {
 		match token {
 			IDLE => self.maintain_network(io),
+			INIT_PUBLIC => self.init_public_interface(io),
 			FIRST_SESSION ... LAST_SESSION => self.connection_timeout(token, io),
 			FIRST_HANDSHAKE ... LAST_HANDSHAKE => self.connection_timeout(token, io),
 			DISCOVERY_REFRESH => {
-				self.discovery.as_ref().unwrap().lock().unwrap().refresh();
+				self.discovery.lock().unwrap().as_mut().unwrap().refresh();
 				io.update_registration(DISCOVERY).expect("Error updating discovery registration");
 			},
 			DISCOVERY_ROUND => {
-				let node_changes = { self.discovery.as_ref().unwrap().lock().unwrap().round() };
+				let node_changes = { self.discovery.lock().unwrap().as_mut().unwrap().round() };
 				if let Some(node_changes) = node_changes {
 					self.update_nodes(io, node_changes);
 				}
@ -896,8 +923,8 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 					connection.lock().unwrap().register_socket(reg, event_loop).expect("Error registering socket");
 				}
 			}
-			DISCOVERY => self.discovery.as_ref().unwrap().lock().unwrap().register_socket(event_loop).expect("Error registering discovery socket"),
-			TCP_ACCEPT => event_loop.register(self.tcp_listener.lock().unwrap().deref(), Token(TCP_ACCEPT), EventSet::all(), PollOpt::edge()).expect("Error registering stream"),
+			DISCOVERY => self.discovery.lock().unwrap().as_ref().unwrap().register_socket(event_loop).expect("Error registering discovery socket"),
+			TCP_ACCEPT => event_loop.register(self.tcp_listener.lock().unwrap().as_ref().unwrap(), Token(TCP_ACCEPT), EventSet::all(), PollOpt::edge()).expect("Error registering stream"),
 			_ => warn!("Unexpected stream registration")
 		}
 	}
@ -919,7 +946,6 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 				}
 			}
 			DISCOVERY => (),
-			TCP_ACCEPT => event_loop.deregister(self.tcp_listener.lock().unwrap().deref()).unwrap(),
 			_ => warn!("Unexpected stream deregistration")
 		}
 	}
@ -938,8 +964,8 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 					connection.lock().unwrap().update_socket(reg, event_loop).expect("Error updating socket");
 				}
 			}
-			DISCOVERY => self.discovery.as_ref().unwrap().lock().unwrap().update_registration(event_loop).expect("Error reregistering discovery socket"),
-			TCP_ACCEPT => event_loop.reregister(self.tcp_listener.lock().unwrap().deref(), Token(TCP_ACCEPT), EventSet::all(), PollOpt::edge()).expect("Error reregistering stream"),
+			DISCOVERY => self.discovery.lock().unwrap().as_ref().unwrap().update_registration(event_loop).expect("Error reregistering discovery socket"),
+			TCP_ACCEPT => event_loop.reregister(self.tcp_listener.lock().unwrap().as_ref().unwrap(), Token(TCP_ACCEPT), EventSet::all(), PollOpt::edge()).expect("Error reregistering stream"),
 			_ => warn!("Unexpected stream update")
 		}
 	}
--- a/util/src/network/service.rs
+++ b/util/src/network/service.rs
@ -42,7 +42,6 @@ impl<Message> NetworkService<Message> where Message: Send + Sync + Clone + 'stat
 		let host = Arc::new(Host::new(config));
 		let stats = host.stats().clone();
 		let host_info = host.client_version();
-		info!("Node URL: {}", host.client_url());
 		try!(io_service.register_handler(host));
 		Ok(NetworkService {
 			io_service: io_service,
--- a/util/src/uint.rs
+++ b/util/src/uint.rs
@ -51,6 +51,339 @@ macro_rules! impl_map_from {
 	}
 }

+#[cfg(not(all(feature="x64asm", target_arch="x86_64")))]
+macro_rules! uint_overflowing_add {
+	($name:ident, $n_words:expr, $self_expr: expr, $other: expr) => ({
+		uint_overflowing_add_reg!($name, $n_words, $self_expr, $other)
+	})
+}
+
+macro_rules! uint_overflowing_add_reg {
+	($name:ident, $n_words:expr, $self_expr: expr, $other: expr) => ({
+		let $name(ref me) = $self_expr;
+		let $name(ref you) = $other;
+		let mut ret = [0u64; $n_words];
+		let mut carry = [0u64; $n_words];
+		let mut b_carry = false;
+		let mut overflow = false;
+
+		for i in 0..$n_words {
+			ret[i] = me[i].wrapping_add(you[i]);
+
+			if ret[i] < me[i] {
+				if i < $n_words - 1 {
+					carry[i + 1] = 1;
+					b_carry = true;
+				} else {
+					overflow = true;
+				}
+			}
+		}
+		if b_carry {
+			let ret = overflowing!($name(ret).overflowing_add($name(carry)), overflow);
+			(ret, overflow)
+		} else {
+			($name(ret), overflow)
+		}
+	})
+}
+
+
+#[cfg(all(feature="x64asm", target_arch="x86_64"))]
+macro_rules! uint_overflowing_add {
+	(U256, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		let mut result: [u64; 4] = unsafe { mem::uninitialized() };
+		let self_t: &[u64; 4] = unsafe { &mem::transmute($self_expr) };
+		let other_t: &[u64; 4] = unsafe { &mem::transmute($other) };
+
+		let overflow: u8;
+		unsafe {
+			asm!("
+				add $9, $0
+				adc $10, $1
+				adc $11, $2
+				adc $12, $3
+				setc %al
+				"
+			: "=r"(result[0]), "=r"(result[1]), "=r"(result[2]), "=r"(result[3]), "={al}"(overflow)
+			: "0"(self_t[0]), "1"(self_t[1]), "2"(self_t[2]), "3"(self_t[3]),
+			  "mr"(other_t[0]), "mr"(other_t[1]), "mr"(other_t[2]), "mr"(other_t[3])
+			:
+			:
+			);
+		}
+		(U256(result), overflow != 0)
+	});
+	(U512, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		let mut result: [u64; 8] = unsafe { mem::uninitialized() };
+		let self_t: &[u64; 8] = unsafe { &mem::transmute($self_expr) };
+		let other_t: &[u64; 8] = unsafe { &mem::transmute($other) };
+
+		let overflow: u8;
+
+		unsafe {
+			asm!("
+				add $15, $0
+				adc $16, $1
+				adc $17, $2
+				adc $18, $3
+				lodsq
+				adc $11, %rax
+				stosq
+				lodsq
+				adc $12, %rax
+				stosq
+				lodsq
+				adc $13, %rax
+				stosq
+				lodsq
+				adc $14, %rax
+				stosq
+				setc %al
+
+				": "=r"(result[0]), "=r"(result[1]), "=r"(result[2]), "=r"(result[3]),
+
+			  "={al}"(overflow) /* $0 - $4 */
+
+            : "{rdi}"(&result[4] as *const u64) /* $5 */
+			  "{rsi}"(&other_t[4] as *const u64) /* $6 */
+			  "0"(self_t[0]), "1"(self_t[1]), "2"(self_t[2]), "3"(self_t[3]),
+		  	  "m"(self_t[4]), "m"(self_t[5]), "m"(self_t[6]), "m"(self_t[7]),
+			  /* $7 - $14 */
+
+			  "mr"(other_t[0]), "mr"(other_t[1]), "mr"(other_t[2]), "mr"(other_t[3]),
+              "m"(other_t[4]), "m"(other_t[5]), "m"(other_t[6]), "m"(other_t[7]) /* $15 - $22 */
+			: "rdi", "rsi"
+			:
+			);
+		}
+		(U512(result), overflow != 0)
+	});
+
+	($name:ident, $n_words:expr, $self_expr: expr, $other: expr) => (
+		uint_overflowing_add_reg!($name, $n_words, $self_expr, $other)
+	)
+}
+
+#[cfg(not(all(feature="x64asm", target_arch="x86_64")))]
+macro_rules! uint_overflowing_sub {
+	($name:ident, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		let res = overflowing!((!$other).overflowing_add(From::from(1u64)));
+		let res = overflowing!($self_expr.overflowing_add(res));
+		(res, $self_expr < $other)
+	})
+}
+
+#[cfg(all(feature="x64asm", target_arch="x86_64"))]
+macro_rules! uint_overflowing_sub {
+	(U256, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		let mut result: [u64; 4] = unsafe { mem::uninitialized() };
+		let self_t: &[u64; 4] = unsafe { &mem::transmute($self_expr) };
+		let other_t: &[u64; 4] = unsafe { &mem::transmute($other) };
+
+		let overflow: u8;
+		unsafe {
+			asm!("
+				sub $9, $0
+				sbb $10, $1
+				sbb $11, $2
+				sbb $12, $3
+				setb %al
+				"
+				: "=r"(result[0]), "=r"(result[1]), "=r"(result[2]), "=r"(result[3]), "={al}"(overflow)
+				: "0"(self_t[0]), "1"(self_t[1]), "2"(self_t[2]), "3"(self_t[3]), "mr"(other_t[0]), "mr"(other_t[1]), "mr"(other_t[2]), "mr"(other_t[3])
+				:
+				:
+			);
+		}
+		(U256(result), overflow != 0)
+	});
+	(U512, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		let mut result: [u64; 8] = unsafe { mem::uninitialized() };
+		let self_t: &[u64; 8] = unsafe { &mem::transmute($self_expr) };
+		let other_t: &[u64; 8] = unsafe { &mem::transmute($other) };
+
+		let overflow: u8;
+
+		unsafe {
+			asm!("
+				sub $15, $0
+				sbb $16, $1
+				sbb $17, $2
+				sbb $18, $3
+				lodsq
+				sbb $19, %rax
+				stosq
+				lodsq
+				sbb $20, %rax
+				stosq
+				lodsq
+				sbb $21, %rax
+				stosq
+				lodsq
+				sbb $22, %rax
+				stosq
+				setb %al
+				"
+			: "=r"(result[0]), "=r"(result[1]), "=r"(result[2]), "=r"(result[3]),
+
+			  "={al}"(overflow) /* $0 - $4 */
+
+			: "{rdi}"(&result[4] as *const u64) /* $5 */
+		 	 "{rsi}"(&self_t[4] as *const u64) /* $6 */
+			  "0"(self_t[0]), "1"(self_t[1]), "2"(self_t[2]), "3"(self_t[3]),
+			  "m"(self_t[4]), "m"(self_t[5]), "m"(self_t[6]), "m"(self_t[7]),
+			  /* $7 - $14 */
+
+			  "m"(other_t[0]), "m"(other_t[1]), "m"(other_t[2]), "m"(other_t[3]),
+			  "m"(other_t[4]), "m"(other_t[5]), "m"(other_t[6]), "m"(other_t[7]) /* $15 - $22 */
+			: "rdi", "rsi"
+			:
+			);
+		}
+		(U512(result), overflow != 0)
+	});
+	($name:ident, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		let res = overflowing!((!$other).overflowing_add(From::from(1u64)));
+		let res = overflowing!($self_expr.overflowing_add(res));
+		(res, $self_expr < $other)
+	})
+}
+
+#[cfg(all(feature="x64asm", target_arch="x86_64"))]
+macro_rules! uint_overflowing_mul {
+	(U256, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		let mut result: [u64; 4] = unsafe { mem::uninitialized() };
+		let self_t: &[u64; 4] = unsafe { &mem::transmute($self_expr) };
+		let other_t: &[u64; 4] = unsafe { &mem::transmute($other) };
+
+		let overflow: u64;
+		unsafe {
+			asm!("
+				mov $5, %rax
+				mulq $9
+				mov %rax, $0
+				mov %rdx, $1
+
+				mov $6, %rax
+				mulq $9
+				add %rax, $1
+				mov %rdx, $2
+
+				mov $5, %rax
+				mulq $10
+				add %rax, $1
+				adc %rdx, $2
+
+				mov $6, %rax
+				mulq $10
+				add %rax, $2
+				mov %rdx, $3
+
+				mov $7, %rax
+				mulq $9
+				add %rax, $2
+				adc %rdx, $3
+
+				mov $5, %rax
+				mulq $11
+    			add %rax, $2
+				adc %rdx, $3
+
+				mov $8, %rax
+				mulq $9
+				adc %rax, $3
+				adc $$0, %rdx
+				mov %rdx, %rcx
+
+				mov $7, %rax
+				mulq $10
+				add %rax, $3
+				adc $$0, %rdx
+				or %rdx, %rcx
+
+				mov $6, %rax
+				mulq $11
+				add %rax, $3
+				adc $$0, %rdx
+				or %rdx, %rcx
+
+				mov $5, %rax
+				mulq $12
+				add %rax, $3
+				adc $$0, %rdx
+				or %rdx, %rcx
+
+				cmpq $$0, %rcx
+				jne 2f
+
+				popcnt $8, %rcx
+				jrcxz 12f
+
+				popcnt $12, %rcx
+				popcnt $11, %rax
+				add %rax, %rcx
+				popcnt $10, %rax
+				add %rax, %rcx
+				jmp 2f
+
+				12:
+				popcnt $12, %rcx
+				jrcxz 11f
+
+				popcnt $7, %rcx
+				popcnt $6, %rax
+				add %rax, %rcx
+
+				cmpq $$0, %rcx
+				jne 2f
+
+				11:
+				popcnt $11, %rcx
+				jrcxz 2f
+				popcnt $7, %rcx
+
+				2:
+				"
+				: /* $0 */ "={r8}"(result[0]), /* $1 */ "={r9}"(result[1]), /* $2 */ "={r10}"(result[2]),
+				  /* $3 */ "={r11}"(result[3]), /* $4 */  "={rcx}"(overflow)
+
+				: /* $5 */ "m"(self_t[0]), /* $6 */ "m"(self_t[1]), /* $7 */  "m"(self_t[2]),
+				  /* $8 */ "m"(self_t[3]), /* $9 */ "m"(other_t[0]), /* $10 */ "m"(other_t[1]),
+				  /* $11 */ "m"(other_t[2]), /* $12 */ "m"(other_t[3])
+           		: "rax", "rdx", "rbx"
+				:
+
+			);
+		}
+		(U256(result), overflow > 0)
+	});
+	($name:ident, $n_words:expr, $self_expr: expr, $other: expr) => (
+		uint_overflowing_mul_reg!($name, $n_words, $self_expr, $other)
+	)
+}
+
+#[cfg(not(all(feature="x64asm", target_arch="x86_64")))]
+macro_rules! uint_overflowing_mul {
+	($name:ident, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		uint_overflowing_mul_reg!($name, $n_words, $self_expr, $other)
+	})
+}
+
+macro_rules! uint_overflowing_mul_reg {
+	($name:ident, $n_words: expr, $self_expr: expr, $other: expr) => ({
+		let mut res = $name::from(0u64);
+		let mut overflow = false;
+		// TODO: be more efficient about this
+		for i in 0..(2 * $n_words) {
+			let v = overflowing!($self_expr.overflowing_mul_u32(($other >> (32 * i)).low_u32()), overflow);
+			let res2 = overflowing!(v.overflowing_shl(32 * i as u32), overflow);
+			res = overflowing!(res.overflowing_add(res2), overflow);
+		}
+		(res, overflow)
+	})
+}
+
 macro_rules! overflowing {
 	($op: expr, $overflow: expr) => (
 		{
@ -297,50 +630,20 @@ macro_rules! construct_uint {
 				(res, overflow)
 			}

+			/// Optimized instructions
+			#[inline(always)]
 			fn overflowing_add(self, other: $name) -> ($name, bool) {
-				let $name(ref me) = self;
-				let $name(ref you) = other;
-				let mut ret = [0u64; $n_words];
-				let mut carry = [0u64; $n_words];
-				let mut b_carry = false;
-				let mut overflow = false;
-
-				for i in 0..$n_words {
-					ret[i] = me[i].wrapping_add(you[i]);
-
-					if ret[i] < me[i] {
-						if i < $n_words - 1 {
-							carry[i + 1] = 1;
-							b_carry = true;
-						} else {
-							overflow = true;
-						}
-					}
-				}
-				if b_carry {
-					let ret = overflowing!($name(ret).overflowing_add($name(carry)), overflow);
-					(ret, overflow)
-				} else {
-					($name(ret), overflow)
-				}
+				uint_overflowing_add!($name, $n_words, self, other)
 			}

+			#[inline(always)]
 			fn overflowing_sub(self, other: $name) -> ($name, bool) {
-				let res = overflowing!((!other).overflowing_add(From::from(1u64)));
-				let res = overflowing!(self.overflowing_add(res));
-				(res, self < other)
+				uint_overflowing_sub!($name, $n_words, self, other)
 			}

+			#[inline(always)]
 			fn overflowing_mul(self, other: $name) -> ($name, bool) {
-				let mut res = $name::from(0u64);
-				let mut overflow = false;
-				// TODO: be more efficient about this
-				for i in 0..(2 * $n_words) {
-					let v = overflowing!(self.overflowing_mul_u32((other >> (32 * i)).low_u32()), overflow);
-					let res2 = overflowing!(v.overflowing_shl(32 * i as u32), overflow);
-					res = overflowing!(res.overflowing_add(res2), overflow);
-				}
-				(res, overflow)
+				uint_overflowing_mul!($name, $n_words, self, other)
 			}

 			fn overflowing_div(self, other: $name) -> ($name, bool) {
@ -391,6 +694,7 @@ macro_rules! construct_uint {
 		}

 		impl $name {
+			#[allow(dead_code)] // not used when multiplied with inline assembly
 			/// Multiplication by u32
 			fn mul_u32(self, other: u32) -> Self {
 				let $name(ref arr) = self;
@ -412,6 +716,7 @@ macro_rules! construct_uint {
 				$name(ret) + $name(carry)
 			}

+			#[allow(dead_code)] // not used when multiplied with inline assembly
 			/// Overflowing multiplication by u32
 			fn overflowing_mul_u32(self, other: u32) -> (Self, bool) {
 				let $name(ref arr) = self;
@ -535,23 +840,9 @@ macro_rules! construct_uint {
 			type Output = $name;

 			fn add(self, other: $name) -> $name {
-				let $name(ref me) = self;
-				let $name(ref you) = other;
-				let mut ret = [0u64; $n_words];
-				let mut carry = [0u64; $n_words];
-				let mut b_carry = false;
-				for i in 0..$n_words {
-					if i < $n_words - 1 {
-						ret[i] = me[i].wrapping_add(you[i]);
-						if ret[i] < me[i] {
-							carry[i + 1] = 1;
-							b_carry = true;
-						}
-					} else {
-						ret[i] = me[i] + you[i];
-					}
-				}
-				if b_carry { $name(ret) + $name(carry) } else { $name(ret) }
+				let (result, overflow) = self.overflowing_add(other);
+				panic_on_overflow!(overflow);
+				result
 			}
 		}

@ -560,9 +851,9 @@ macro_rules! construct_uint {

 			#[inline]
 			fn sub(self, other: $name) -> $name {
-				panic_on_overflow!(self < other);
-				let res = overflowing!((!other).overflowing_add(From::from(1u64)));
-				overflowing!(self.overflowing_add(res))
+				let (result, overflow) = self.overflowing_sub(other);
+				panic_on_overflow!(overflow);
+				result
 			}
 		}

@ -570,15 +861,9 @@ macro_rules! construct_uint {
 			type Output = $name;

 			fn mul(self, other: $name) -> $name {
-				let mut res = $name::from(0u64);
-				// TODO: be more efficient about this
-				for i in 0..(2 * $n_words) {
-					let v = self.mul_u32((other >> (32 * i)).low_u32());
-					let (r, overflow) = v.overflowing_shl(32 * i as u32);
-					panic_on_overflow!(overflow);
-					res = res + r;
-				}
-				res
+				let (result, overflow) = self.overflowing_mul(other);
+				panic_on_overflow!(overflow);
+				result
 			}
 		}

@ -1171,8 +1456,6 @@ mod tests {
 		);
 	}

-
-
 	#[test]
 	#[should_panic]
 	pub fn uint256_mul_overflow_panic() {
@ -1291,5 +1574,173 @@ mod tests {
 	fn display_uint_zero() {
 		assert_eq!(format!("{}", U256::from(0)), "0");
 	}
+
+    #[test]
+    fn u512_multi_adds() {
+		let (result, _) = U512([0, 0, 0, 0, 0, 0, 0, 0]).overflowing_add(U512([0, 0, 0, 0, 0, 0, 0, 0]));
+		assert_eq!(result, U512([0, 0, 0, 0, 0, 0, 0, 0]));
+
+		let (result, _) = U512([1, 0, 0, 0, 0, 0, 0, 1]).overflowing_add(U512([1, 0, 0, 0, 0, 0, 0, 1]));
+		assert_eq!(result, U512([2, 0, 0, 0, 0, 0, 0, 2]));
+
+		let (result, _) = U512([0, 0, 0, 0, 0, 0, 0, 1]).overflowing_add(U512([0, 0, 0, 0, 0, 0, 0, 1]));
+		assert_eq!(result, U512([0, 0, 0, 0, 0, 0, 0, 2]));
+
+		let (result, _) = U512([0, 0, 0, 0, 0, 0, 2, 1]).overflowing_add(U512([0, 0, 0, 0, 0, 0, 3, 1]));
+		assert_eq!(result, U512([0, 0, 0, 0, 0, 0, 5, 2]));
+
+		let (result, _) = U512([1, 2, 3, 4, 5, 6, 7, 8]).overflowing_add(U512([9, 10, 11, 12, 13, 14, 15, 16]));
+		assert_eq!(result, U512([10, 12, 14, 16, 18, 20, 22, 24]));
+
+		let (_, overflow) = U512([0, 0, 0, 0, 0, 0, 2, 1]).overflowing_add(U512([0, 0, 0, 0, 0, 0, 3, 1]));
+		assert!(!overflow);
+
+		let (_, overflow) = U512([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX])
+			.overflowing_add(U512([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX]));
+		assert!(overflow);
+
+		let (_, overflow) = U512([0, 0, 0, 0, 0, 0, 0, ::std::u64::MAX])
+			.overflowing_add(U512([0, 0, 0, 0, 0, 0, 0, ::std::u64::MAX]));
+        assert!(overflow);
+
+		let (_, overflow) = U512([0, 0, 0, 0, 0, 0, 0, ::std::u64::MAX])
+			.overflowing_add(U512([0, 0, 0, 0, 0, 0, 0, 0]));
+		assert!(!overflow);
+	}
+
+    #[test]
+    fn u256_multi_adds() {
+        let (result, _) = U256([0, 0, 0, 0]).overflowing_add(U256([0, 0, 0, 0]));
+        assert_eq!(result, U256([0, 0, 0, 0]));
+
+        let (result, _) = U256([0, 0, 0, 1]).overflowing_add(U256([0, 0, 0, 1]));
+        assert_eq!(result, U256([0, 0, 0, 2]));
+
+        let (result, overflow) = U256([0, 0, 2, 1]).overflowing_add(U256([0, 0, 3, 1]));
+        assert_eq!(result, U256([0, 0, 5, 2]));
+        assert!(!overflow);
+
+        let (_, overflow) = U256([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX])
+			.overflowing_add(U256([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX]));
+        assert!(overflow);
+
+        let (_, overflow) = U256([0, 0, 0, ::std::u64::MAX]).overflowing_add(U256([0, 0, 0, ::std::u64::MAX]));
+        assert!(overflow);
+    }
+
+
+    #[test]
+    fn u256_multi_subs() {
+        let (result, _) = U256([0, 0, 0, 0]).overflowing_sub(U256([0, 0, 0, 0]));
+        assert_eq!(result, U256([0, 0, 0, 0]));
+
+        let (result, _) = U256([0, 0, 0, 1]).overflowing_sub(U256([0, 0, 0, 1]));
+        assert_eq!(result, U256([0, 0, 0, 0]));
+
+        let (_, overflow) = U256([0, 0, 2, 1]).overflowing_sub(U256([0, 0, 3, 1]));
+        assert!(overflow);
+
+        let (result, overflow) = U256([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX])
+                                .overflowing_sub(U256([::std::u64::MAX/2, ::std::u64::MAX/2, ::std::u64::MAX/2, ::std::u64::MAX/2]));
+        assert!(!overflow);
+        assert_eq!(U256([::std::u64::MAX/2+1, ::std::u64::MAX/2+1, ::std::u64::MAX/2+1, ::std::u64::MAX/2+1]), result);
+
+        let (result, overflow) = U256([0, 0, 0, 1]).overflowing_sub(U256([0, 0, 1, 0]));
+        assert!(!overflow);
+        assert_eq!(U256([0, 0, ::std::u64::MAX, 0]), result);
+
+        let (result, overflow) = U256([0, 0, 0, 1]).overflowing_sub(U256([1, 0, 0, 0]));
+        assert!(!overflow);
+        assert_eq!(U256([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, 0]), result);
+    }
+
+
+	#[test]
+	fn u512_multi_subs() {
+		let (result, _) = U512([0, 0, 0, 0, 0, 0, 0, 0]).overflowing_sub(U512([0, 0, 0, 0, 0, 0, 0, 0]));
+		assert_eq!(result, U512([0, 0, 0, 0, 0, 0, 0, 0]));
+
+		let (result, _) = U512([10, 9, 8, 7, 6, 5, 4, 3]).overflowing_sub(U512([9, 8, 7, 6, 5, 4, 3, 2]));
+		assert_eq!(result, U512([1, 1, 1, 1, 1, 1, 1, 1]));
+
+		let (_, overflow) = U512([10, 9, 8, 7, 6, 5, 4, 3]).overflowing_sub(U512([9, 8, 7, 6, 5, 4, 3, 2]));
+		assert!(!overflow);
+
+		let (_, overflow) = U512([9, 8, 7, 6, 5, 4, 3, 2]).overflowing_sub(U512([10, 9, 8, 7, 6, 5, 4, 3]));
+		assert!(overflow);
+	}
+
+	#[test]
+	fn u256_multi_muls() {
+        let (result, _) = U256([0, 0, 0, 0]).overflowing_mul(U256([0, 0, 0, 0]));
+        assert_eq!(U256([0, 0, 0, 0]), result);
+
+        let (result, _) = U256([1, 0, 0, 0]).overflowing_mul(U256([1, 0, 0, 0]));
+        assert_eq!(U256([1, 0, 0, 0]), result);
+
+        let (result, _) = U256([5, 0, 0, 0]).overflowing_mul(U256([5, 0, 0, 0]));
+        assert_eq!(U256([25, 0, 0, 0]), result);
+
+        let (result, _) = U256([0, 5, 0, 0]).overflowing_mul(U256([0, 5, 0, 0]));
+        assert_eq!(U256([0, 0, 25, 0]), result);
+
+        let (result, _) = U256([0, 0, 0, 1]).overflowing_mul(U256([1, 0, 0, 0]));
+        assert_eq!(U256([0, 0, 0, 1]), result);
+
+        let (result, _) = U256([0, 0, 0, 5]).overflowing_mul(U256([2, 0, 0, 0]));
+        assert_eq!(U256([0, 0, 0, 10]), result);
+
+        let (result, _) = U256([0, 0, 1, 0]).overflowing_mul(U256([0, 5, 0, 0]));
+        assert_eq!(U256([0, 0, 0, 5]), result);
+
+        let (result, _) = U256([0, 0, 8, 0]).overflowing_mul(U256([0, 0, 7, 0]));
+        assert_eq!(U256([0, 0, 0, 0]), result);
+
+        let (result, _) = U256([2, 0, 0, 0]).overflowing_mul(U256([0, 5, 0, 0]));
+        assert_eq!(U256([0, 10, 0, 0]), result);
+
+        let (result, _) = U256([::std::u64::MAX, 0, 0, 0]).overflowing_mul(U256([::std::u64::MAX, 0, 0, 0]));
+        assert_eq!(U256([1, ::std::u64::MAX-1, 0, 0]), result);
+
+        let (result, _) = U256([0, 0, 0, ::std::u64::MAX]).overflowing_mul(U256([0, 0, 0, ::std::u64::MAX]));
+        assert_eq!(U256([0, 0, 0, 0]), result);
+
+        let (result, _) = U256([1, 0, 0, 0]).overflowing_mul(U256([0, 0, 0, ::std::u64::MAX]));
+        assert_eq!(U256([0, 0, 0, ::std::u64::MAX]), result);
+
+        let (result, _) = U256([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX])
+			.overflowing_mul(U256([::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX, ::std::u64::MAX]));
+        assert_eq!(U256([1, 0, 0, 0]), result);
+	}
+
+    #[test]
+    fn u256_multi_muls_overflow() {
+        let (_, overflow) = U256([1, 0, 0, 0]).overflowing_mul(U256([0, 0, 0, 0]));
+        assert!(!overflow);
+
+        let (_, overflow) = U256([1, 0, 0, 0]).overflowing_mul(U256([0, 0, 0, ::std::u64::MAX]));
+        assert!(!overflow);
+
+        let (_, overflow) = U256([0, 1, 0, 0]).overflowing_mul(U256([0, 0, 0, ::std::u64::MAX]));
+        assert!(overflow);
+
+        let (_, overflow) = U256([0, 1, 0, 0]).overflowing_mul(U256([0, 1, 0, 0]));
+        assert!(!overflow);
+
+        let (_, overflow) = U256([0, 1, 0, ::std::u64::MAX]).overflowing_mul(U256([0, 1, 0, ::std::u64::MAX]));
+        assert!(overflow);
+
+        let (_, overflow) = U256([0, ::std::u64::MAX, 0, 0]).overflowing_mul(U256([0, ::std::u64::MAX, 0, 0]));
+        assert!(!overflow);
+
+        let (_, overflow) = U256([1, 0, 0, 0]).overflowing_mul(U256([10, 0, 0, 0]));
+        assert!(!overflow);
+
+        let (_, overflow) = U256([2, 0, 0, 0]).overflowing_mul(U256([0, 0, 0, ::std::u64::MAX / 2]));
+        assert!(!overflow);
+
+        let (_, overflow) = U256([0, 0, 8, 0]).overflowing_mul(U256([0, 0, 7, 0]));
+        assert!(overflow);
+    }
 }