diff --git a/examples/testNode.js b/examples/testNode.js
index 8e53b73..494f157 100644
--- a/examples/testNode.js
+++ b/examples/testNode.js
@@ -1,8 +1,28 @@
 const { Account, Wallet } = require('@harmony/account');
-const { isAddress, isPrivateKey, numberToHex } = require('@harmony/utils');
+const {
+  isAddress,
+  isPrivateKey,
+  numberToHex,
+  numToStr,
+  hexToNumber,
+  Unit,
+  strip0x,
+} = require('@harmony/utils');
 const { HttpProvider, Messenger } = require('@harmony/network');
 const { Transaction } = require('@harmony/transaction');
-const { hexlify, BN } = require('@harmony/crypto');
+const {
+  arrayify,
+  hexlify,
+  BN,
+  encode,
+  decode,
+  getContractAddress,
+  recoverAddress,
+  recoverPublicKey,
+  keccak256,
+  hexZeroPad,
+  getAddressFromPublicKey,
+} = require('@harmony/crypto');
 
 const msgr = new Messenger(new HttpProvider('https://dev-api.zilliqa.com'));
 const wallet = new Wallet(msgr);
@@ -58,15 +78,44 @@ const acc = wallet.addByPrivateKey(
   '0xc3886f791236bf31fe8fd7522a7b12808700deb9c159826fc99236c74614118b',
 );
 
-console.log(txn.getRLPUnsigned()[0]);
+// console.log(txn.getRLPUnsigned()[0]);
 
 const signed = wallet
   .getAccount(acc.address)
   .signTransaction(txn, false)
-  .then(console.log);
-
+  .then((tx) => {
+    const newTx = tx.recover(tx.unsignedTxnHash);
+    // console.log(newTx);
+    acc.signTransaction(newTx, false, 'rlp').then((signed) => {
+      console.log(signed);
+    });
+  });
+
+// recoverAddress();
 // console.log(wallet.messenger);
 // console.log(hexlify(0));
 
 // 0xda8003049401234567890123456789012345678901234567890580;
 // 0xda8003049401234567890123456789012345678901234567890580;
+/**
+ * { name: 'nonce', length: 32, fix: false },
+ { name: 'gasPrice', length: 32, fix: false, transform: 'hex' },
+ { name: 'gasLimit', length: 32, fix: false, transform: 'hex' },
+ { name: 'to', length: 20, fix: true },
+ { name: 'value', length: 32, fix: false, transform: 'hex' },
+ { name: 'data', fix: false },
+ */
+// const [nonce, gasPrice, gasLimit, to, value, data] = decode(
+//   txn.getRLPUnsigned()[0],
+// );
+
+// console.log({
+//   nonce: new BN(strip0x(hexToNumber(nonce))).toNumber(),
+//   gasPrice: hexToNumber(gasPrice !== '0x' ? gasPrice : '0x00'),
+//   gasLimit: hexToNumber(gasLimit !== '0x' ? gasLimit : '0x00'),
+//   to: hexToNumber(to !== '0x' ? to : '0x00'),
+//   value: hexToNumber(value !== '0x' ? value : '0x00'),
+//   data: hexToNumber(data !== '0x' ? data : '0x00'),
+// });
+
+// console.log(getContractAddress(acc.publicKey, 248));
diff --git a/packages/harmony-account/src/account.ts b/packages/harmony-account/src/account.ts
index f2cef35..a824324 100644
--- a/packages/harmony-account/src/account.ts
+++ b/packages/harmony-account/src/account.ts
@@ -152,6 +152,7 @@ class Account {
       const balanceObject: any = await this.getBalance();
       transaction.setParams({
         ...transaction.txParams,
+        from: this.address || '0x',
         nonce: balanceObject.nonce + 1,
       });
     }
@@ -161,7 +162,7 @@ class Account {
         this.privateKey,
       );
       return transaction.map((obj: any) => {
-        return { ...obj, signature, txnHash };
+        return { ...obj, signature, txnHash, from: this.address };
       });
     } else {
       // TODO: if we use other encode method, eg. protobuf, we should implement this
diff --git a/packages/harmony-account/src/index.ts b/packages/harmony-account/src/index.ts
index 73927b0..88db089 100644
--- a/packages/harmony-account/src/index.ts
+++ b/packages/harmony-account/src/index.ts
@@ -1,2 +1,4 @@
 export * from './account';
 export * from './wallet';
+export * from './types';
+export * from './utils';
diff --git a/packages/harmony-crypto/src/bytes.ts b/packages/harmony-crypto/src/bytes.ts
index 5dec6e5..152f1b2 100644
--- a/packages/harmony-crypto/src/bytes.ts
+++ b/packages/harmony-crypto/src/bytes.ts
@@ -341,54 +341,55 @@ export function isSignature(value: any): value is Signature {
 }
 
 export function splitSignature(signature: Arrayish | Signature): Signature {
-  let v: number | undefined = 0;
-  let r = '0x';
-  let s = '0x';
+  if (signature !== undefined) {
+    let v = 0;
+    let r = '0x';
+    let s = '0x';
+
+    if (isSignature(signature)) {
+      if (signature.v == null && signature.recoveryParam == null) {
+        errors.throwError(
+          'at least on of recoveryParam or v must be specified',
+          errors.INVALID_ARGUMENT,
+          { argument: 'signature', value: signature },
+        );
+      }
+      r = hexZeroPad(signature.r, 32);
+      s = hexZeroPad(signature.s, 32);
 
-  if (isSignature(signature)) {
-    if (signature.v == null && signature.recoveryParam == null) {
-      errors.throwError(
-        'at least on of recoveryParam or v must be specified',
-        errors.INVALID_ARGUMENT,
-        { argument: 'signature', value: signature },
-      );
-    }
-    r = hexZeroPad(signature.r, 32);
-    s = hexZeroPad(signature.s, 32);
+      v = signature.v || 0;
+      if (typeof v === 'string') {
+        v = parseInt(v, 16);
+      }
 
-    v = signature.v;
-    if (typeof v === 'string') {
-      v = parseInt(v, 16);
-    }
+      let recoveryParam = signature.recoveryParam || 0;
+      if (recoveryParam == null && signature.v != null) {
+        recoveryParam = 1 - (v % 2);
+      }
+      v = 27 + recoveryParam;
+    } else {
+      const bytes: Uint8Array = arrayify(signature) || new Uint8Array();
+      if (bytes.length !== 65) {
+        throw new Error('invalid signature');
+      }
+      r = hexlify(bytes.slice(0, 32));
+      s = hexlify(bytes.slice(32, 64));
 
-    let recoveryParam = signature.recoveryParam || 1;
-    if (recoveryParam == null && signature.v != null) {
-      recoveryParam = 1 - (typeof v !== 'number' ? 0 : v % 2);
-    }
-    v = 27 + recoveryParam;
-  } else {
-    const bytes: Uint8Array | null = arrayify(signature);
-    if (bytes === null) {
-      throw new Error('arrayify failed');
-    }
-    if (bytes.length !== 65) {
-      throw new Error('invalid signature');
+      v = bytes[64];
+      if (v !== 27 && v !== 28) {
+        v = 27 + (v % 2);
+      }
     }
-    r = hexlify(bytes.slice(0, 32));
-    s = hexlify(bytes.slice(32, 64));
 
-    v = bytes[64];
-    if (v !== 27 && v !== 28) {
-      v = 27 + (v % 2);
-    }
+    return {
+      r,
+      s,
+      recoveryParam: v - 27,
+      v,
+    };
+  } else {
+    throw new Error('signature is not found');
   }
-
-  return {
-    r,
-    s,
-    recoveryParam: v - 27,
-    v,
-  };
 }
 
 export function joinSignature(signature: Signature): string {
diff --git a/packages/harmony-crypto/src/keyTool.ts b/packages/harmony-crypto/src/keyTool.ts
index 45749fb..259baaa 100644
--- a/packages/harmony-crypto/src/keyTool.ts
+++ b/packages/harmony-crypto/src/keyTool.ts
@@ -5,6 +5,7 @@ import * as errors from './errors';
 import { keccak256 } from './keccak256';
 import { randomBytes } from './random';
 import { isPrivateKey, strip0x } from '@harmony/utils';
+import { encode } from './rlp';
 
 const secp256k1 = elliptic.ec('secp256k1');
 
@@ -63,8 +64,8 @@ export const getPublic = (privateKey: string, compress?: boolean): string => {
  */
 export const getAddressFromPublicKey = (publicKey: string): string => {
   const ecKey = secp256k1.keyFromPublic(publicKey.slice(2), 'hex');
-  const publickHash = ecKey.getPublic(false, 'hex');
-  const address = '0x' + keccak256('0x' + publickHash.slice(2)).slice(-40);
+  const publicHash = ecKey.getPublic(false, 'hex');
+  const address = '0x' + keccak256('0x' + publicHash.slice(2)).slice(-40);
   return address;
 };
 
@@ -110,12 +111,71 @@ export const sign = (
   if (!isPrivateKey(privateKey)) {
     throw new Error(`${privateKey} is not PrivateKey`);
   }
+
   const keyPair = secp256k1.keyFromPrivate(strip0x(privateKey), 'hex');
   const signature = keyPair.sign(bytes.arrayify(digest), { canonical: true });
-  return {
+  const publicKey = '0x' + keyPair.getPublic(true, 'hex');
+  const result = {
     recoveryParam: signature.recoveryParam,
     r: bytes.hexZeroPad('0x' + signature.r.toString(16), 32),
     s: bytes.hexZeroPad('0x' + signature.s.toString(16), 32),
     v: 27 + signature.recoveryParam,
   };
+
+  if (verifySignature(digest, result, publicKey)) {
+    return result;
+  } else {
+    throw new Error('signing process failed');
+  }
 };
+
+export function getContractAddress(from: string, nonce: number): string {
+  if (!from) {
+    throw new Error('missing from address');
+  }
+
+  const addr = keccak256(
+    encode([from, bytes.stripZeros(bytes.hexlify(nonce))]),
+  );
+  return '0x' + addr.substring(26);
+}
+
+export function verifySignature(
+  digest: bytes.Arrayish,
+  signature: bytes.Signature,
+  publicKey: string,
+): boolean {
+  return recoverPublicKey(digest, signature) === publicKey;
+}
+
+export function recoverPublicKey(
+  digest: bytes.Arrayish | string,
+  signature: bytes.Signature | string,
+): string {
+  const sig = bytes.splitSignature(signature);
+  const rs = { r: bytes.arrayify(sig.r), s: bytes.arrayify(sig.s) };
+
+  ////
+  const recovered = secp256k1.recoverPubKey(
+    bytes.arrayify(digest),
+    rs,
+    sig.recoveryParam,
+  );
+
+  const key = recovered.encode('hex', false);
+  const ecKey = secp256k1.keyFromPublic(key, 'hex');
+  const publicKey = '0x' + ecKey.getPublic(true, 'hex');
+
+  ///
+
+  return publicKey;
+}
+
+export function recoverAddress(
+  digest: bytes.Arrayish | string,
+  signature: bytes.Signature | string,
+): string {
+  return getAddressFromPublicKey(
+    recoverPublicKey(bytes.arrayify(digest) || new Uint8Array(), signature),
+  );
+}
diff --git a/packages/harmony-transaction/src/transaction.ts b/packages/harmony-transaction/src/transaction.ts
index 67bb711..8dc5a03 100644
--- a/packages/harmony-transaction/src/transaction.ts
+++ b/packages/harmony-transaction/src/transaction.ts
@@ -1,15 +1,19 @@
 import {
   BN,
   encode,
+  // keccak256,
+  // decode,
   // toChecksumAddress,
   arrayify,
   hexlify,
   stripZeros,
   Signature,
   splitSignature,
+  // hexZeroPad,
 } from '@harmony/crypto';
 import { add0xToString } from '@harmony/utils';
 import { TxParams } from './types';
+import { recover } from './utils';
 
 export const transactionFields = [
   { name: 'nonce', length: 32, fix: false },
@@ -22,7 +26,7 @@ export const transactionFields = [
 
 class Transaction {
   //   private hash?: string;
-  //   private from?: string;
+  private from: string;
   private nonce: number | string;
   private to: string;
   private gasLimit: BN;
@@ -33,11 +37,10 @@ class Transaction {
   private txnHash: string;
   private unsignedTxnHash: string;
   private signature: Signature;
-  //   private r?: string;
-  //   private s?: string;
-  //   private v?: number;
+
   // constructor
   constructor(params?: TxParams) {
+    this.from = params ? params.from : '0x';
     this.nonce = params ? params.nonce : 0;
     this.gasPrice = params ? params.gasPrice : new BN(0);
     this.gasLimit = params ? params.gasLimit : new BN(0);
@@ -115,8 +118,15 @@ class Transaction {
 
     return encode(raw);
   }
+
+  recover(txnHash: string): Transaction {
+    this.setParams(recover(txnHash));
+    return this;
+  }
+
   get txParams(): TxParams {
     return {
+      from: this.from || '',
       nonce: this.nonce || 0,
       gasPrice: this.gasPrice || new BN(0),
       gasLimit: this.gasLimit || new BN(0),
@@ -130,6 +140,7 @@ class Transaction {
     };
   }
   setParams(params: TxParams) {
+    this.from = params ? params.from : '0x';
     this.nonce = params ? params.nonce : 0;
     this.gasPrice = params ? params.gasPrice : new BN(0);
     this.gasLimit = params ? params.gasLimit : new BN(0);
diff --git a/packages/harmony-transaction/src/types.ts b/packages/harmony-transaction/src/types.ts
index 0e5c5d3..9843742 100644
--- a/packages/harmony-transaction/src/types.ts
+++ b/packages/harmony-transaction/src/types.ts
@@ -1,5 +1,6 @@
 import { BN, Signature } from '@harmony/crypto';
 export interface TxParams {
+  from: string;
   to: string;
   nonce: number | string;
   gasLimit: BN;
diff --git a/packages/harmony-transaction/src/utils.ts b/packages/harmony-transaction/src/utils.ts
index e69de29..c3d4269 100644
--- a/packages/harmony-transaction/src/utils.ts
+++ b/packages/harmony-transaction/src/utils.ts
@@ -0,0 +1,114 @@
+import { hexToNumber, isHex, isAddress, strip0x } from '@harmony/utils';
+import {
+  decode,
+  encode,
+  keccak256,
+  hexlify,
+  BN,
+  hexZeroPad,
+  recoverAddress,
+} from '@harmony/crypto';
+import { TxParams } from './types';
+
+export const handleNumber = (value: string) => {
+  if (isHex(value) && value === '0x') {
+    return hexToNumber('0x00');
+  } else if (isHex(value) && value !== '0x') {
+    return hexToNumber(value);
+  } else {
+    return value;
+  }
+};
+
+export const handleAddress = (value: string): string => {
+  if (value === '0x') {
+    return '0x';
+  } else if (isAddress(value)) {
+    return value;
+  } else {
+    return '0x';
+  }
+};
+
+export const recover = (rawTransaction: string) => {
+  const transaction = decode(rawTransaction);
+  if (transaction.length !== 9 && transaction.length !== 6) {
+    throw new Error('invalid rawTransaction');
+  }
+
+  const tx: TxParams = {
+    from: '0x',
+    txnHash: '0x',
+    unsignedTxnHash: '0x',
+    nonce: new BN(strip0x(handleNumber(transaction[0]))).toNumber(),
+    gasPrice: new BN(strip0x(handleNumber(transaction[1]))),
+    gasLimit: new BN(strip0x(handleNumber(transaction[2]))),
+    to: handleAddress(transaction[3]),
+    value: new BN(strip0x(handleNumber(transaction[4]))),
+    data: transaction[5],
+    chainId: 0,
+    signature: {
+      r: '',
+      s: '',
+      recoveryParam: 0,
+      v: 0,
+    },
+  };
+
+  // Legacy unsigned transaction
+  if (transaction.length === 6) {
+    tx.unsignedTxnHash = rawTransaction;
+    return tx;
+  }
+
+  try {
+    tx.signature.v = new BN(strip0x(handleNumber(transaction[6]))).toNumber();
+  } catch (error) {
+    throw error;
+  }
+
+  tx.signature.r = hexZeroPad(transaction[7], 32);
+  tx.signature.s = hexZeroPad(transaction[8], 32);
+
+  if (
+    new BN(strip0x(handleNumber(tx.signature.r))).isZero() &&
+    new BN(strip0x(handleNumber(tx.signature.s))).isZero()
+  ) {
+    // EIP-155 unsigned transaction
+    tx.chainId = tx.signature.v;
+    tx.signature.v = 0;
+  } else {
+    // Signed Tranasaction
+
+    tx.chainId = Math.floor((tx.signature.v - 35) / 2);
+    if (tx.chainId < 0) {
+      tx.chainId = 0;
+    }
+
+    let recoveryParam = tx.signature.v - 27;
+
+    const raw = transaction.slice(0, 6);
+
+    if (tx.chainId !== 0) {
+      raw.push(hexlify(tx.chainId));
+      raw.push('0x');
+      raw.push('0x');
+      recoveryParam -= tx.chainId * 2 + 8;
+    }
+
+    const digest = keccak256(encode(raw));
+    try {
+      tx.from = recoverAddress(digest, {
+        r: hexlify(tx.signature.r),
+        s: hexlify(tx.signature.s),
+        recoveryParam,
+      });
+    } catch (error) {
+      throw error;
+    }
+
+    tx.txnHash = keccak256(rawTransaction);
+  }
+
+  return tx;
+};
diff --git a/packages/harmony-utils/src/transformers.ts b/packages/harmony-utils/src/transformers.ts
index 84df4f7..1369d88 100644
--- a/packages/harmony-utils/src/transformers.ts
+++ b/packages/harmony-utils/src/transformers.ts
@@ -9,8 +9,30 @@ export const enum Units {
   szabo = 'szabo',
   finney = 'finney',
   ether = 'ether',
+  Kether = 'Kether',
+  Mether = 'Mether',
+  Gether = 'Gether',
+  Tether = 'Tether',
 }
 
+export const unitMap = new Map([
+  [Units.wei, '1'],
+  [Units.kwei, '1000'], // 1e3 wei
+  [Units.Mwei, '1000000'], // 1e6 wei
+  [Units.Gwei, '1000000000'], // 1e9 wei
+  [Units.szabo, '1000000000000'], // 1e12 wei
+  [Units.finney, '1000000000000000'], // 1e15 wei
+  [Units.ether, '1000000000000000000'], // 1e18 wei
+  [Units.Kether, '1000000000000000000000'], // 1e21 wei
+  [Units.Mether, '1000000000000000000000000'], // 1e24 wei
+  [Units.Gether, '1000000000000000000000000000'], // 1e27 wei
+  [Units.Tether, '1000000000000000000000000000000'], // 1e30 wei
+]);
+
+const DEFAULT_OPTIONS = {
+  pad: false,
+};
+
 export const numberToString = (
   obj: BN | number | string,
   radix: number = 10,
@@ -26,6 +48,25 @@ export const numberToString = (
   }
 };
 
+export const numToStr = (input: any) => {
+  if (typeof input === 'string') {
+    if (!input.match(/^-?[0-9.]+$/)) {
+      throw new Error(
+        `while converting number to string, invalid number value '${input}', should be a number matching (^-?[0-9.]+).`,
+      );
+    }
+    return input;
+  } else if (typeof input === 'number') {
+    return String(input);
+  } else if (BN.isBN(input)) {
+    return input.toString(10);
+  }
+
+  throw new Error(
+    `while converting number to string, invalid number value '${input}' type ${typeof input}.`,
+  );
+};
+
 export const add0xToString = (obj: string): string => {
   if (isString(obj) && !obj.startsWith('-')) {
     return '0x' + obj.replace('0x', '');
@@ -49,19 +90,297 @@ export const numberToHex = (obj: any): string => {
 };
 
 export const hexToNumber = (hex: string): string => {
-  if (isHex(hex)) {
+  if (isHex(hex) && hex[0] !== '-') {
     return new BN(strip0x(hex), 'hex').toString();
+  } else if (isHex(hex) && hex[0] === '-') {
+    const result: BN = new BN(hex.substring(3), 16);
+    return result.mul(new BN(-1)).toString();
   } else {
     throw new Error(`${hex} is not hex number`);
   }
 };
 
-export const toWei = (obj: any): string => {
-  return '';
+export const toWei = (input: BN | string, unit: Units): BN => {
+  try {
+    let inputStr = numToStr(input);
+    const baseStr = unitMap.get(unit);
+
+    if (!baseStr) {
+      throw new Error(`No unit of type ${unit} exists.`);
+    }
+
+    const baseNumDecimals = baseStr.length - 1;
+    const base = new BN(baseStr, 10);
+
+    // Is it negative?
+    const isNegative = inputStr.substring(0, 1) === '-';
+    if (isNegative) {
+      inputStr = inputStr.substring(1);
+    }
+
+    if (inputStr === '.') {
+      throw new Error(`Cannot convert ${inputStr} to wei.`);
+    }
+
+    // Split it into a whole and fractional part
+    const comps = inputStr.split('.'); // eslint-disable-line
+    if (comps.length > 2) {
+      throw new Error(`Cannot convert ${inputStr} to wei.`);
+    }
+
+    let [whole, fraction] = comps;
+
+    if (!whole) {
+      whole = '0';
+    }
+    if (!fraction) {
+      fraction = '0';
+    }
+    if (fraction.length > baseNumDecimals) {
+      throw new Error(`Cannot convert ${inputStr} to Qa.`);
+    }
+
+    while (fraction.length < baseNumDecimals) {
+      fraction += '0';
+    }
+
+    const wholeBN = new BN(whole);
+    const fractionBN = new BN(fraction);
+    let wei = wholeBN.mul(base).add(fractionBN);
+
+    if (isNegative) {
+      wei = wei.neg();
+    }
+
+    return new BN(wei.toString(10), 10);
+  } catch (error) {
+    throw error;
+  }
 };
 
-export const fromWei = (obj: any): string => {
-  return '';
+export const fromWei = (
+  wei: BN | string,
+  unit: Units,
+  options: any = DEFAULT_OPTIONS,
+): string => {
+  try {
+    const weiBN: BN = !BN.isBN(wei) ? new BN(wei) : wei;
+
+    if (unit === 'wei') {
+      return weiBN.toString(10);
+    }
+
+    const baseStr = unitMap.get(unit);
+
+    if (!baseStr) {
+      throw new Error(`No unit of type ${unit} exists.`);
+    }
+
+    const base = new BN(baseStr, 10);
+    const baseNumDecimals = baseStr.length - 1;
+
+    let fraction = weiBN
+      .abs()
+      .mod(base)
+      .toString(10);
+
+    // prepend 0s to the fraction half
+    while (fraction.length < baseNumDecimals) {
+      fraction = `0${fraction}`;
+    }
+
+    if (!options.pad) {
+      /* eslint-disable prefer-destructuring */
+      const matchFraction = fraction.match(/^([0-9]*[1-9]|0)(0*)/);
+      fraction = matchFraction ? matchFraction[1] : '0';
+    }
+
+    const whole = weiBN.div(base).toString(10);
+
+    return fraction === '0' ? `${whole}` : `${whole}.${fraction}`;
+  } catch (error) {
+    throw error;
+  }
 };
 
-export class Unit {}
+export class Unit {
+  static from(str: BN | string) {
+    return new Unit(str);
+  }
+
+  static Wei(str: BN | string) {
+    return new Unit(str).asWei();
+  }
+  static Kwei(str: BN | string) {
+    return new Unit(str).asKwei();
+  }
+  static Mwei(str: BN | string) {
+    return new Unit(str).asMwei();
+  }
+  static Gwei(str: BN | string) {
+    return new Unit(str).asGwei();
+  }
+  static Szabo(str: BN | string) {
+    return new Unit(str).asSzabo();
+  }
+  static Finney(str: BN | string) {
+    return new Unit(str).asFinney();
+  }
+  static Ether(str: BN | string) {
+    return new Unit(str).asEther();
+  }
+  static Kether(str: BN | string) {
+    return new Unit(str).asKether();
+  }
+  static Mether(str: BN | string) {
+    return new Unit(str).asMether();
+  }
+  static Gether(str: BN | string) {
+    return new Unit(str).asGether();
+  }
+  static Tether(str: BN | string) {
+    return new Unit(str).asTether();
+  }
+
+  wei?: BN;
+  unit: BN | string;
+
+  constructor(str: BN | string) {
+    this.unit = str;
+  }
+
+  asWei() {
+    this.wei = new BN(this.unit);
+    return this;
+  }
+  asKwei() {
+    this.wei = toWei(this.unit, Units.kwei);
+    return this;
+  }
+  asMwei() {
+    this.wei = toWei(this.unit, Units.Mwei);
+    return this;
+  }
+  asGwei() {
+    this.wei = toWei(this.unit, Units.Gwei);
+    return this;
+  }
+  asSzabo() {
+    this.wei = toWei(this.unit, Units.szabo);
+    return this;
+  }
+  asFinney() {
+    this.wei = toWei(this.unit, Units.finney);
+    return this;
+  }
+  asEther() {
+    this.wei = toWei(this.unit, Units.ether);
+    return this;
+  }
+  asKether() {
+    this.wei = toWei(this.unit, Units.Kether);
+    return this;
+  }
+  asMether() {
+    this.wei = toWei(this.unit, Units.Mether);
+    return this;
+  }
+  asGether() {
+    this.wei = toWei(this.unit, Units.Gether);
+    return this;
+  }
+  asTether() {
+    this.wei = toWei(this.unit, Units.Gether);
+    return this;
+  }
+
+  toWei() {
+    return this.wei;
+  }
+
+  toKwei() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.kwei);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toGwei() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.Gwei);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toMwei() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.Mwei);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toSzabo() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.szabo);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  tofinney() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.finney);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toEther() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.ether);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toKether() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.Kether);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toMether() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.Mether);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toGether() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.Gether);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toTether() {
+    if (this.wei) {
+      return fromWei(this.wei, Units.Tether);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+
+  toWeiString() {
+    if (this.wei) {
+      return this.wei.toString();
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+  toHex() {
+    if (this.wei) {
+      return numberToHex(this.wei);
+    } else {
+      throw new Error('error transforming');
+    }
+  }
+}
diff --git a/typings/elliptic.d.ts b/typings/elliptic.d.ts
index ad5e127..2b83bdb 100644
--- a/typings/elliptic.d.ts
+++ b/typings/elliptic.d.ts
@@ -31,6 +31,11 @@ declare namespace Elliptic {
   }
 
   interface EC {
+    recoverPubKey(
+      arg0: Uint8Array | null,
+      rs: { r: Uint8Array | null; s: Uint8Array | null },
+      recoveryParam: number | undefined,
+    ): any;
     curve: Curve;
     genKeyPair(opt?: GenKeyPairOpt): KeyPair;
     keyFromPrivate(priv: string, enc: string): KeyPair;