diff --git a/Cargo.toml b/Cargo.toml
index 4a1917e4f..cc0953f8f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,4 +13,5 @@ rustc-serialize = "0.3"
 arrayvec = "0.3"
 mio = "0.*"
 rand = "0.*"
-tiny-keccak = "0.1"
+tiny-keccak = "0.2"
+rocksdb = "0.2.1"
diff --git a/src/db.rs b/src/db.rs
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/hash.rs b/src/hash.rs
index 081b0df02..17f1c6c71 100644
--- a/src/hash.rs
+++ b/src/hash.rs
@@ -95,23 +95,23 @@ macro_rules! impl_hash {
 	}
 }
 
-impl_hash!(Hash64, 8);
-impl_hash!(Hash128, 16);
+impl_hash!(H64, 8);
+impl_hash!(H128, 16);
 impl_hash!(Address, 20);
-impl_hash!(Hash256, 32);
-impl_hash!(Hash512, 64);
-impl_hash!(Hash520, 65);
-impl_hash!(Hash1024, 128);
-impl_hash!(Hash2048, 256);
-impl_hash!(Hash4096, 512);
+impl_hash!(H256, 32);
+impl_hash!(H512, 64);
+impl_hash!(H520, 65);
+impl_hash!(H1024, 128);
+impl_hash!(H2048, 256);
+impl_hash!(H4096, 512);
 
 #[test]
 fn hash() {
-	let h = Hash64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef]);
-	assert_eq!(Hash64::from_str("0123456789abcdef").unwrap(), h);
+	let h = H64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef]);
+	assert_eq!(H64::from_str("0123456789abcdef").unwrap(), h);
 	assert_eq!(format!("{}", h), "0123456789abcdef");
 	assert_eq!(format!("{:?}", h), "0123456789abcdef");
 	assert!(h == h);
-	assert!(h != Hash64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xee]));
-	assert!(h != Hash64([0; 8]));
+	assert!(h != H64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xee]));
+	assert!(h != H64([0; 8]));
 }
diff --git a/src/lib.rs b/src/lib.rs
index 44ffc106f..9d1d25808 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,8 @@
 extern crate rustc_serialize;
 extern crate mio;
 extern crate rand;
+extern crate rocksdb;
+extern crate tiny_keccak;
 #[macro_use]
 extern crate log;
 
@@ -12,6 +14,7 @@ pub mod uint;
 pub mod bytes;
 pub mod rlp;
 pub mod vector;
+pub mod db;
 
 //pub mod network;