diff --git a/src/accountant.rs b/src/accountant.rs
index 3af394965..61838382c 100644
--- a/src/accountant.rs
+++ b/src/accountant.rs
@@ -2,7 +2,8 @@
 //! event log to record transactions. Its users can deposit funds and
 //! transfer funds to other users.
 
-use log::{Entry, Sha256Hash};
+use hash::Sha256Hash;
+use log::Entry;
 use event::Event;
 use transaction::Transaction;
 use signature::{PublicKey, Signature};
diff --git a/src/accountant_skel.rs b/src/accountant_skel.rs
index 4c6c12a98..9296b6a17 100644
--- a/src/accountant_skel.rs
+++ b/src/accountant_skel.rs
@@ -2,7 +2,8 @@ use std::io;
 use accountant::Accountant;
 use transaction::Transaction;
 use signature::PublicKey;
-use log::{Entry, Sha256Hash};
+use hash::Sha256Hash;
+use log::Entry;
 use std::net::UdpSocket;
 use bincode::{deserialize, serialize};
 
diff --git a/src/accountant_stub.rs b/src/accountant_stub.rs
index ea713a9b5..1bded971e 100644
--- a/src/accountant_stub.rs
+++ b/src/accountant_stub.rs
@@ -7,7 +7,8 @@ use std::io;
 use bincode::{deserialize, serialize};
 use transaction::Transaction;
 use signature::{PublicKey, Signature};
-use log::{Entry, Sha256Hash};
+use hash::Sha256Hash;
+use log::Entry;
 use ring::signature::Ed25519KeyPair;
 use accountant_skel::{Request, Response};
 
diff --git a/src/bin/demo.rs b/src/bin/demo.rs
index bdbad0ba2..76c27dc30 100644
--- a/src/bin/demo.rs
+++ b/src/bin/demo.rs
@@ -1,7 +1,8 @@
 extern crate silk;
 
 use silk::historian::Historian;
-use silk::log::{verify_slice, Entry, Sha256Hash};
+use silk::hash::Sha256Hash;
+use silk::log::{verify_slice, Entry};
 use silk::signature::{generate_keypair, get_pubkey};
 use silk::transaction::Transaction;
 use silk::event::Event;
diff --git a/src/genesis.rs b/src/genesis.rs
index 01bcd1416..6ef4151ad 100644
--- a/src/genesis.rs
+++ b/src/genesis.rs
@@ -3,7 +3,8 @@
 use event::Event;
 use transaction::Transaction;
 use signature::{generate_keypair, get_pubkey, PublicKey};
-use log::{create_entries, hash, Entry, Sha256Hash};
+use log::{create_entries, Entry};
+use hash::{hash, Sha256Hash};
 use ring::rand::SystemRandom;
 use ring::signature::Ed25519KeyPair;
 use untrusted::Input;
diff --git a/src/hash.rs b/src/hash.rs
new file mode 100644
index 000000000..5efb933f5
--- /dev/null
+++ b/src/hash.rs
@@ -0,0 +1,19 @@
+use generic_array::GenericArray;
+use generic_array::typenum::U32;
+use sha2::{Digest, Sha256};
+
+pub type Sha256Hash = GenericArray<u8, U32>;
+
+/// Return a Sha256 hash for the given data.
+pub fn hash(val: &[u8]) -> Sha256Hash {
+    let mut hasher = Sha256::default();
+    hasher.input(val);
+    hasher.result()
+}
+
+/// Return the hash of the given hash extended with the given value.
+pub fn extend_and_hash(id: &Sha256Hash, val: &[u8]) -> Sha256Hash {
+    let mut hash_data = id.to_vec();
+    hash_data.extend_from_slice(val);
+    hash(&hash_data)
+}
diff --git a/src/historian.rs b/src/historian.rs
index 03605a247..f0683c8f7 100644
--- a/src/historian.rs
+++ b/src/historian.rs
@@ -5,7 +5,8 @@ use std::thread::{spawn, JoinHandle};
 use std::collections::HashSet;
 use std::sync::mpsc::{sync_channel, Receiver, SyncSender};
 use std::time::Instant;
-use log::{hash, Entry, Sha256Hash};
+use hash::{hash, Sha256Hash};
+use log::Entry;
 use logger::{ExitReason, Logger};
 use signature::Signature;
 use event::Event;
diff --git a/src/lib.rs b/src/lib.rs
index 91cbf8b70..4551c6833 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
 #![cfg_attr(feature = "unstable", feature(test))]
+pub mod hash;
 pub mod log;
 pub mod logger;
 pub mod event;
diff --git a/src/log.rs b/src/log.rs
index 1da66d778..6a13f3abe 100644
--- a/src/log.rs
+++ b/src/log.rs
@@ -13,15 +13,11 @@
 /// fastest processor. Duration should therefore be estimated by assuming that the hash
 /// was generated by the fastest processor at the time the entry was logged.
 
-use generic_array::GenericArray;
-use generic_array::typenum::U32;
+use hash::{extend_and_hash, hash, Sha256Hash};
 use serde::Serialize;
 use event::Event;
-use sha2::{Digest, Sha256};
 use rayon::prelude::*;
 
-pub type Sha256Hash = GenericArray<u8, U32>;
-
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
 pub struct Entry<T> {
     pub num_hashes: u64,
@@ -50,20 +46,6 @@ impl<T: Serialize> Entry<T> {
     }
 }
 
-/// Return a Sha256 hash for the given data.
-pub fn hash(val: &[u8]) -> Sha256Hash {
-    let mut hasher = Sha256::default();
-    hasher.input(val);
-    hasher.result()
-}
-
-/// Return the hash of the given hash extended with the given value.
-pub fn extend_and_hash(id: &Sha256Hash, val: &[u8]) -> Sha256Hash {
-    let mut hash_data = id.to_vec();
-    hash_data.extend_from_slice(val);
-    hash(&hash_data)
-}
-
 /// Creates the hash 'num_hashes' after start_hash. If the event contains
 /// signature, the final hash will be a hash of both the previous ID and
 /// the signature.
diff --git a/src/logger.rs b/src/logger.rs
index 8fcf101f6..8f47bc97c 100644
--- a/src/logger.rs
+++ b/src/logger.rs
@@ -7,7 +7,8 @@
 
 use std::sync::mpsc::{Receiver, SyncSender, TryRecvError};
 use std::time::{Duration, Instant};
-use log::{create_entry_mut, Entry, Sha256Hash};
+use hash::Sha256Hash;
+use log::{create_entry_mut, Entry};
 use event::Event;
 use serde::Serialize;
 use std::fmt::Debug;
diff --git a/src/transaction.rs b/src/transaction.rs
index f0be7c1d8..119335866 100644
--- a/src/transaction.rs
+++ b/src/transaction.rs
@@ -4,7 +4,7 @@ use signature::{get_pubkey, verify_signature, PublicKey, Signature};
 use ring::signature::Ed25519KeyPair;
 use serde::Serialize;
 use bincode::serialize;
-use log::Sha256Hash;
+use hash::Sha256Hash;
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
 pub struct Transaction<T> {
@@ -51,8 +51,8 @@ impl<T: Serialize> Transaction<T> {
 mod tests {
     use super::*;
     use bincode::{deserialize, serialize};
-    use log::*;
     use signature::*;
+    use hash::hash;
 
     #[test]
     fn test_claim() {