diff --git a/Cargo.toml b/Cargo.toml
index 2c4be9b..8b0111e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,7 +19,7 @@ name = "ots-info"
 path = "src/bin/ots_info.rs"
 
 [dependencies]
+bitcoin_hashes = "0.12.0"
 env_logger = "0.4"
 log = "0.3"
-rust-crypto = "0.2"
 
diff --git a/src/lib.rs b/src/lib.rs
index f43a45f..66fff5d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -23,7 +23,7 @@
 #![deny(unused_mut)]
 #![deny(missing_docs)]
 
-extern crate crypto;
+extern crate bitcoin_hashes;
 #[macro_use] extern crate log;
 
 pub mod attestation;
diff --git a/src/op.rs b/src/op.rs
index 220d80d..9ad3cf2 100644
--- a/src/op.rs
+++ b/src/op.rs
@@ -18,13 +18,10 @@
 //! timestamps.
 //!
 
-use crypto::digest::Digest;
-use crypto::sha1::Sha1;
-use crypto::sha2::Sha256;
-use crypto::ripemd160::Ripemd160;
 use std::fmt;
 use std::io::{Read, Write};
 
+use bitcoin_hashes::{Hash, ripemd160, sha1, sha256};
 use error::Error;
 use hex::Hexed;
 use ser;
@@ -100,25 +97,13 @@ impl Op {
     pub fn execute(&self, input: &[u8]) -> Vec<u8> {
         match *self {
             Op::Sha1 => {
-                let mut ret = vec![0; 20];
-                let mut hasher = Sha1::new();
-                hasher.input(input);
-                hasher.result(&mut ret);
-                ret
+                sha1::Hash::hash(&input).to_byte_array().to_vec()
             }
             Op::Sha256 => {
-                let mut ret = vec![0; 32];
-                let mut hasher = Sha256::new();
-                hasher.input(input);
-                hasher.result(&mut ret);
-                ret
+                sha256::Hash::hash(&input).to_byte_array().to_vec()
             }
             Op::Ripemd160 => {
-                let mut ret = vec![0; 20];
-                let mut hasher = Ripemd160::new();
-                hasher.input(input);
-                hasher.result(&mut ret);
-                ret
+                ripemd160::Hash::hash(&input).to_byte_array().to_vec()
             }
             Op::Hexlify => {
                 format!("{}", Hexed(input)).into_bytes()