diff --git a/lib/hdkey.js b/lib/hdkey.js
index 77e1a44..3c28932 100644
--- a/lib/hdkey.js
+++ b/lib/hdkey.js
@@ -152,6 +152,14 @@ HDKey.prototype.deriveChild = function (index) {
   return hd
 }
 
+HDKey.prototype.sign = function (hash) {
+  return secp256k1.sign(hash, this.privateKey).signature
+}
+
+HDKey.prototype.verify = function (hash, signature) {
+  return secp256k1.verify(hash, signature, this.publicKey)
+}
+
 HDKey.prototype.toJSON = function () {
   return {
     xpriv: this.privateExtendedKey,