diff --git a/Cargo.lock b/Cargo.lock
index c930b8ff9..e8f5b66b1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -545,6 +545,7 @@ dependencies = [
  "bigint 3.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
+ "plain_hasher 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2192,6 +2193,14 @@ name = "pkg-config"
 version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "plain_hasher"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crunchy 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "podio"
 version = "0.1.5"
@@ -3371,6 +3380,7 @@ dependencies = [
 "checksum phf_generator 0.7.14 (registry+https://github.com/rust-lang/crates.io-index)" = "db005608fd99800c8c74106a7c894cf582055b689aa14a79462cefdcb7dc1cc3"
 "checksum phf_shared 0.7.14 (registry+https://github.com/rust-lang/crates.io-index)" = "fee4d039930e4f45123c9b15976cf93a499847b6483dc09c42ea0ec4940f2aa6"
 "checksum pkg-config 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "3a8b4c6b8165cd1a1cd4b9b120978131389f64bdaf456435caa41e630edba903"
+"checksum plain_hasher 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "83ae80873992f511142c07d0ec6c44de5636628fdb7e204abd655932ea79d995"
 "checksum podio 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e5422a1ee1bc57cc47ae717b0137314258138f38fd5f3cea083f43a9725383a0"
 "checksum pretty_assertions 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2412f3332a07c7a2a50168988dcc184f32180a9758ad470390e5f55e089f6b6e"
 "checksum primal 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "0e31b86efadeaeb1235452171a66689682783149a6249ff334a2c5d8218d00a4"
diff --git a/util/bigint/Cargo.toml b/util/bigint/Cargo.toml
index 477925334..6797ce2bb 100644
--- a/util/bigint/Cargo.toml
+++ b/util/bigint/Cargo.toml
@@ -13,6 +13,7 @@ rustc-hex = "1.0"
 rand = "0.3.12"
 libc = "0.2"
 heapsize = { version = "0.4", optional = true }
+plain_hasher = "0.1"
 
 [features]
 x64asm_arithmetic=[]
diff --git a/util/bigint/src/hash.rs b/util/bigint/src/hash.rs
index ddb9bc622..316062bc4 100644
--- a/util/bigint/src/hash.rs
+++ b/util/bigint/src/hash.rs
@@ -16,6 +16,7 @@ use std::collections::{HashMap, HashSet};
 use rand::{Rand, Rng};
 use rand::os::OsRng;
 use rustc_hex::{FromHex, FromHexError};
+use plain_hasher::PlainHasher;
 use bigint::U256;
 use libc::{c_void, memcmp};
 
@@ -446,52 +447,6 @@ impl_hash!(H2048, 256);
 known_heap_size!(0, H32, H64, H128, H160, H256, H264, H512, H520, H1024, H2048);
 // Specialized HashMap and HashSet
 
-/// Hasher that just takes 8 bytes of the provided value.
-/// May only be used for keys which are 32 bytes.
-pub struct PlainHasher {
-	prefix: u64,
-}
-
-impl Default for PlainHasher {
-	#[inline]
-	fn default() -> PlainHasher {
-		PlainHasher {
-			prefix: 0,
-		}
-	}
-}
-
-impl PlainHasher {
-	#[inline]
-	fn mut_prefix(&mut self) -> &mut [u8; 8] {
-		unsafe { ::std::mem::transmute(&mut self.prefix) }
-	}
-}
-
-impl Hasher for PlainHasher {
-	#[inline]
-	fn finish(&self) -> u64 {
-		self.prefix
-	}
-
-	#[inline]
-	fn write(&mut self, bytes: &[u8]) {
-		debug_assert!(bytes.len() == 32);
-
-		unsafe {
-			let mut bytes_ptr = bytes.as_ptr();
-			let mut prefix_ptr = self.mut_prefix().as_mut_ptr();
-
-			for _ in 0..8 {
-				*prefix_ptr ^= *bytes_ptr ^ *bytes_ptr.offset(8) ^ *bytes_ptr.offset(16) ^ *bytes_ptr.offset(24);
-
-				bytes_ptr = bytes_ptr.offset(1);
-				prefix_ptr = prefix_ptr.offset(1);
-			}
-		}
-	}
-}
-
 /// Specialized version of `HashMap` with H256 keys and fast hashing function.
 pub type H256FastMap<T> = HashMap<H256, T, BuildHasherDefault<PlainHasher>>;
 /// Specialized version of `HashSet` with H256 keys and fast hashing function.
diff --git a/util/bigint/src/lib.rs b/util/bigint/src/lib.rs
index 7a85de6a1..1b1b5d488 100644
--- a/util/bigint/src/lib.rs
+++ b/util/bigint/src/lib.rs
@@ -14,6 +14,7 @@ extern crate rand;
 extern crate rustc_hex;
 extern crate bigint;
 extern crate libc;
+extern crate plain_hasher;
 
 #[cfg(feature="heapsizeof")]
 #[macro_use]