diff --git a/.gitignore b/.gitignore
index e383173..6467800 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@ build
 node_modules
 .DS_Store
 .idea
+libra-web.iml
diff --git a/packages/libra-web-account/KeyFactory.ts b/packages/libra-web-account/KeyFactory.ts
index bd7f597..052780d 100644
--- a/packages/libra-web-account/KeyFactory.ts
+++ b/packages/libra-web-account/KeyFactory.ts
@@ -12,10 +12,12 @@ import { Mnemonic } from './Mnemonic'
 export class Seed {
   public static fromMnemonic(words: string[] | Mnemonic, salt: string = 'LIBRA'): Seed {
     const mnemonic: Mnemonic = Array.isArray(words) ? new Mnemonic(words) : words
-    const mnemonicBytes = mnemonic.toBytes()
-    const parsedSalt = `${KeyPrefixes.MnemonicSalt}${salt}`
-
-    const bytes = new Pbkdf('sha256').extract(mnemonicBytes, parsedSalt, 2048, 32)
+    const bytes = new Pbkdf('sha3-256').pbkdf2(
+        mnemonic.toBytes(),
+        Buffer.from(`${KeyPrefixes.MnemonicSalt}${salt}`),
+        2048,
+        32,
+    )
     return new Seed(bytes)
   }
   public readonly data: Uint8Array
@@ -38,7 +40,7 @@ export class KeyFactory {
 
   constructor(seed: Seed) {
     this.seed = seed
-    this.hkdf = new Hkdf('sha256')
+    this.hkdf = new Hkdf('sha3-256')
     this.masterPrk = this.hkdf.extract(this.seed.data, KeyPrefixes.MasterKeySalt)
   }
 
@@ -47,7 +49,12 @@ export class KeyFactory {
    *
    */
   public generateKey(childDepth: number): KeyPair {
-    const info = `${KeyPrefixes.DerivedKey}${childDepth}`
+    const childDepthBuffer = Buffer.alloc(8)
+    childDepthBuffer.writeBigUInt64LE(BigInt(childDepth))
+    const info = Buffer.concat([
+      Uint8Array.from(Buffer.from(KeyPrefixes.DerivedKey)),
+      Uint8Array.from(childDepthBuffer),
+    ]);
     const secretKey = this.hkdf.expand(this.masterPrk, info, 32)
 
     return KeyPair.fromSecretKey(secretKey)
diff --git a/packages/libra-web-core-utils/crypto/Hkdf.ts b/packages/libra-web-core-utils/crypto/Hkdf.ts
index fed59ab..c19e83e 100644
--- a/packages/libra-web-core-utils/crypto/Hkdf.ts
+++ b/packages/libra-web-core-utils/crypto/Hkdf.ts
@@ -1,6 +1,7 @@
 /* tslint:disable */
 const hkdf = require('futoin-hkdf')
 /* tslint:enable */
+type BuffString = Buffer | string;
 
 // Todo: Update implementation to work not only with Node
 export class Hkdf {
@@ -16,7 +17,7 @@ export class Hkdf {
     return new Uint8Array(prk)
   }
 
-  public expand(prk: Uint8Array, info: string, outputLen: number): Uint8Array {
+  public expand(prk: Uint8Array, info: BuffString, outputLen: number): Uint8Array {
     const prkBuffer = Buffer.from(prk)
     const okm = hkdf.expand(this.hashAlgorithm, this.hashLength, prkBuffer, outputLen, info)
     return new Uint8Array(okm)
diff --git a/packages/libra-web-core-utils/crypto/Pbkdf.ts b/packages/libra-web-core-utils/crypto/Pbkdf.ts
index 9a4e283..0e01413 100644
--- a/packages/libra-web-core-utils/crypto/Pbkdf.ts
+++ b/packages/libra-web-core-utils/crypto/Pbkdf.ts
@@ -1,4 +1,4 @@
-import crypto from 'crypto'
+import crypto, {BinaryLike} from 'crypto'
 
 export class Pbkdf {
   private readonly digestAlgorithm: string
@@ -9,4 +9,36 @@ export class Pbkdf {
   public extract(password: Uint8Array, salt: string, iterations: number, outputLen: number) {
     return new Uint8Array(crypto.pbkdf2Sync(Buffer.from(password), salt, iterations, outputLen, this.digestAlgorithm))
   }
+
+  public pbkdf2(password: BinaryLike, salt: Buffer, iterations: number, outputLen: number) {
+    const hmacLength = crypto.createHmac(this.digestAlgorithm, 'test').digest().length;
+    const outputBuffer = Buffer.alloc(outputLen);
+    const hmacOutput = Buffer.alloc(hmacLength);
+    const block = Buffer.alloc(salt.length + 4);
+    const leftLength = Math.ceil(outputLen / hmacLength);
+    const rightLength = outputLen - (leftLength - 1) * hmacLength;
+    salt.copy(block, 0, 0, salt.length);
+    for (let i = 1; i <= leftLength; i++) {
+      block.writeUInt32BE(i, salt.length);
+      let hmac = crypto
+          .createHmac(this.digestAlgorithm, password)
+          .update(block)
+          .digest();
+      hmac.copy(hmacOutput, 0, 0, hmacLength);
+      for (let j = 1; j < iterations; j++) {
+        hmac = crypto
+            .createHmac(this.digestAlgorithm, password)
+            .update(hmac)
+            .digest();
+        for (let k = 0; k < hmacLength; k++) {
+          // tslint:disable-next-line:no-bitwise
+          hmacOutput[k] ^= hmac[k];
+        }
+      }
+      const destPos = (i - 1) * hmacLength;
+      const len = i === leftLength ? rightLength : hmacLength;
+      hmacOutput.copy(outputBuffer, destPos, 0, len);
+    }
+    return outputBuffer;
+  }
 }
diff --git a/test/query.test.ts b/test/query.test.ts
index 308fc97..f199004 100644
--- a/test/query.test.ts
+++ b/test/query.test.ts
@@ -15,7 +15,7 @@ describe('LibraClient.query*()', () => {
         console.log('User 1 address is', account1Address.toHex())
         let account1State = await client.getAccountState(account1Address)
 
-        const account2 = wallet.getAccount(0)
+        const account2 = wallet.getAccount(1)
         const account2Address = account2.getAddress()
         console.log('User 2 address is', account2Address.toHex())
         let account2State = await client.getAccountState(account2Address)