diff --git a/packages/caver-utils/src/index.js b/packages/caver-utils/src/index.js
index c0247069..995953bd 100644
--- a/packages/caver-utils/src/index.js
+++ b/packages/caver-utils/src/index.js
@@ -318,13 +318,21 @@ const unitKlayToEthMap = {
     TKLAY: 'tether',
 }
 
-const getKlayUnitValue = function(unit) {
-    unit = unit || 'KLAY'
+const getKlayUnitValue = function(u) {
+    let unit = u || 'KLAY'
+
+    if (_.isObject(u) && u.unit) unit = u.unit
+
     if (!unitKlayMap[unit]) {
         throw new Error(
             `This unit "${unit}" doesn't exist, please use the one of the following units${JSON.stringify(unitKlayMap, null, 2)}`
         )
     }
+
+    if (u && u.pebFactor !== undefined && KlayUnit[u.unit].pebFactor !== u.pebFactor) {
+        throw new Error(`peb factor does not match with given unit`)
+    }
+
     return unit
 }
 
@@ -378,7 +386,6 @@ const toPeb = function(number, unit) {
  * @return {string} The string number.
  */
 const convertFromPeb = function(amount, unitString) {
-    if (_.isObject(unitString) && unitString.unit) unitString = unitString.unit
     const converted = fromPeb(amount, unitString)
     return utils.isBN(converted) ? converted.toString(10) : converted
 }
@@ -400,7 +407,6 @@ const convertFromPeb = function(amount, unitString) {
  * @return {string|BN}
  */
 const convertToPeb = function(number, unitString) {
-    if (_.isObject(unitString) && unitString.unit) unitString = unitString.unit
     const converted = toPeb(number, unitString)
     return utils.isBN(converted) ? converted.toString(10) : converted
 }
@@ -555,6 +561,9 @@ const stripHexPrefix = function(str) {
  * @return {SignatureData}
  */
 const decodeSignature = signature => {
+    if (Buffer.byteLength(stripHexPrefix(signature), 'hex') !== 65)
+        throw new Error(`Invalid signature: The length of raw signature must be 65 byte.`)
+
     const ret = Account.decodeSignature(signature).map(sig => utils.makeEven(utils.trimLeadingZero(sig)))
     return new SignatureData(ret)
 }
diff --git a/packages/caver-utils/src/utils.js b/packages/caver-utils/src/utils.js
index 355e7060..58c39b24 100644
--- a/packages/caver-utils/src/utils.js
+++ b/packages/caver-utils/src/utils.js
@@ -1453,14 +1453,17 @@ const recover = (message, signature, isHashed = false) => {
  * @inner
  *
  * @method publicKeyToAddress
- * @param {string} publicKey The public key string to get the address.
+ * @param {string} pubKey The public key string to get the address.
  * @return {string}
  */
-const publicKeyToAddress = publicKey => {
-    publicKey = publicKey.slice(0, 2) === '0x' ? publicKey : `0x${publicKey}`
+const publicKeyToAddress = pubKey => {
+    let publicKey = pubKey.slice(0, 2) === '0x' ? pubKey : `0x${pubKey}`
 
     if (isCompressedPublicKey(publicKey)) publicKey = decompressPublicKey(publicKey)
 
+    // With '0x' prefix, 65 bytes in uncompressed format.
+    if (Buffer.byteLength(publicKey, 'hex') !== 65) throw new Error(`Invalid public key: ${pubKey}`)
+
     const publicHash = Hash.keccak256(publicKey)
     const address = `0x${publicHash.slice(-40)}`
 
diff --git a/packages/caver-wallet/src/keyring/signatureData.js b/packages/caver-wallet/src/keyring/signatureData.js
index 32940ec5..5b43351e 100644
--- a/packages/caver-wallet/src/keyring/signatureData.js
+++ b/packages/caver-wallet/src/keyring/signatureData.js
@@ -162,6 +162,20 @@ class SignatureData {
     toString() {
         return this.v + this.r + this.s
     }
+
+    /**
+     * Checks that the signature data is the same.
+     *
+     * @example
+     * const isEqual = signatureData.isEqual([ '0x1b', '0xc6901...', '0x642d8...' ])
+     *
+     * @param {Array.<string>|SignatureData} sig - The ECDSA signatureData to compare
+     * @return {boolean}
+     */
+    isEqual(sig) {
+        sig = new SignatureData(sig)
+        return this.toString() === sig.toString()
+    }
 }
 
 /**