diff --git a/packages/harmony-crypto/src/keyTool.ts b/packages/harmony-crypto/src/keyTool.ts
index d96d947..4bd6d7b 100644
--- a/packages/harmony-crypto/src/keyTool.ts
+++ b/packages/harmony-crypto/src/keyTool.ts
@@ -5,9 +5,16 @@ import { keccak256 } from './keccak256';
 import { randomBytes } from './random';
 
 const secp256k1 = elliptic.ec('secp256k1');
+// const { curve } = secp256k1;
 
+/**
+ * @function generatePrivateKey
+ * @description generatePrivate key using `eth-lib` settings
+ * @return {string}
+ */
 export const generatePrivateKey = (): string => {
   const entropy: string = '0x' + randomBytes(16);
+
   const innerHex: string = keccak256(
     bytes.concat(['0x' + randomBytes(32), entropy || '0x' + randomBytes(32)]),
   );
@@ -19,25 +26,44 @@ export const generatePrivateKey = (): string => {
   return outerHex;
 };
 
+/**
+ * @function getPubkeyFromPrivateKey
+ * @param  {string} privateKey - private key String
+ * @return {string}
+ */
 export const getPubkeyFromPrivateKey = (privateKey: string): string => {
   const buffer = new Buffer(privateKey.slice(2), 'hex');
   const ecKey = secp256k1.keyFromPrivate(buffer);
-  const pubK = '0x' + ecKey.getPublic(false, 'hex').slice(2);
-  const publicKey = keccak256(pubK);
+  const publicKey = '0x' + ecKey.getPublic(true, 'hex');
   return publicKey;
 };
 
+/**
+ * @function getAddressFromPrivateKey
+ * @param  {string} privateKey - private key string
+ * @return {string} address with `length = 40`
+ */
 export const getAddressFromPrivateKey = (privateKey: string): string => {
   const publicKey = getPubkeyFromPrivateKey(privateKey);
   const address = '0x' + publicKey.slice(-40);
   return address;
 };
 
+/**
+ * @function getAddressFromPublicKey
+ * @param  {string} publicKey - public key string
+ * @return {string} address with `length = 40`
+ */
 export const getAddressFromPublicKey = (publicKey: string): string => {
   const address = '0x' + publicKey.slice(-40);
   return address;
 };
 
+/**
+ * @function toChecksumAddress
+ * @param  {string} address - raw address
+ * @return {string} checksumed address
+ */
 export const toChecksumAddress = (address: string): string => {
   if (typeof address !== 'string' || !address.match(/^0x[0-9A-Fa-f]{40}$/)) {
     errors.throwError('invalid address', errors.INVALID_ARGUMENT, {