diff --git a/app/App.tsx b/app/App.tsx
index 1ff5ea1a7..9acfab021 100644
--- a/app/App.tsx
+++ b/app/App.tsx
@@ -38,7 +38,7 @@ import { config } from "@gluestack-ui/config" // Optional if you want to use def
 
 // @ts-ignore
 import PassportReader from 'react-native-passport-reader';
-import {checkInputs, getFirstName} from './utils/checks';
+import {getFirstName, formatDuration, formatProof} from './utils/utils';
 import {
   DEFAULT_PNUMBER,
   DEFAULT_DOB,
@@ -46,9 +46,17 @@ import {
   DEFAULT_ADDRESS,
   LOCAL_IP,
 } from '@env';
-import {DataHash, PassportData} from './types/passportData';
-import {arraysAreEqual, bytesToBigDecimal, dataHashesObjToArray, formatAndConcatenateDataHashes, formatDuration, formatMrz, formatProof, splitToWords} from './utils/utils';
-import {hash, toUnsignedByte} from './utils/computeEContent';
+import {DataHash, PassportData} from '../common/src/utils/types';
+import {
+  hash,
+  toUnsignedByte,
+  checkInputs,
+  bytesToBigDecimal,
+  dataHashesObjToArray,
+  formatAndConcatenateDataHashes,
+  formatMrz,
+  splitToWords
+} from '../common/src/utils/utils';
 
 console.log('DEFAULT_PNUMBER', DEFAULT_PNUMBER);
 console.log('LOCAL_IP', LOCAL_IP);
diff --git a/app/metro.config.js b/app/metro.config.js
index ad8f87b6d..2dc574587 100644
--- a/app/metro.config.js
+++ b/app/metro.config.js
@@ -1,4 +1,11 @@
 const {getDefaultConfig, mergeConfig} = require('@react-native/metro-config');
+const path = require('path');
+const extraNodeModules = {
+  'common': path.resolve(__dirname + '/../common'),
+};
+const watchFolders = [
+  path.resolve(__dirname + '/../common')
+];
 
 /**
  * Metro configuration
@@ -6,6 +13,11 @@ const {getDefaultConfig, mergeConfig} = require('@react-native/metro-config');
  *
  * @type {import('metro-config').MetroConfig}
  */
-const config = {};
+const config = {
+  resolver: {
+    extraNodeModules,
+  },
+  watchFolders,
+};
 
 module.exports = mergeConfig(getDefaultConfig(__dirname), config);
diff --git a/app/package.json b/app/package.json
index 8ec90c0d3..94c17a9be 100644
--- a/app/package.json
+++ b/app/package.json
@@ -39,6 +39,7 @@
     "@types/react-native-dotenv": "^0.2.0",
     "@types/react-test-renderer": "^18.0.0",
     "babel-jest": "^29.2.1",
+    "babel-plugin-module-resolver": "^5.0.0",
     "eslint": "^8.19.0",
     "jest": "^29.2.1",
     "metro-react-native-babel-preset": "0.76.7",
diff --git a/app/scripts/mrzToSig.ts b/app/scripts/mrzToSig.ts
deleted file mode 100644
index ce9e5c52c..000000000
--- a/app/scripts/mrzToSig.ts
+++ /dev/null
@@ -1,94 +0,0 @@
-import * as crypto from 'crypto';
-import {
-  arraysAreEqual,
-  dataHashesObjToArray,
-  formatMrz,
-  assembleMrz,
-  findTimeOfSignature,
-  parsePubKeyString,
-  formatAndConcatenateDataHashes,
-  assembleEContent,
-} from '../utils/utils';
-import * as forge from 'node-forge';
-import passportData from '../server/passportData.json';
-import {DataHash} from '../types/passportData';
-
-// This script tests the whole flow from MRZ to signature
-// The passportData is imported from passportData.json written by the server
-
-const mrz = passportData.mrz;
-
-console.log('mrz: ', mrz);
-
-// Transforms the dataHashes object into an array of arrays
-const dataHashes = passportData.dataGroupHashes as DataHash[];
-
-const mrzHash = hash(formatMrz(mrz));
-
-console.log('mrzHash:', mrzHash);
-console.log(
-  'mrzHash === dataHashes[0][1] ?',
-  arraysAreEqual(mrzHash, dataHashes[0][1] as number[]),
-);
-
-const concatenatedDataHashes = formatAndConcatenateDataHashes(
-  mrzHash,
-  dataHashes,
-);
-
-const concatenatedDataHashesHashDigest = hash(concatenatedDataHashes);
-
-// check that concatenatedDataHashesHashDigest is at the right place of passportData.eContent
-const sliceOfEContent = passportData.eContent.slice(72, 72 + 32);
-
-console.log(
-  'Are they equal ?',
-  arraysAreEqual(sliceOfEContent, concatenatedDataHashesHashDigest),
-);
-
-// now let's verify the signature
-// const {modulus, exponent} = parsePubKeyString(passportData.publicKey);
-// Create the public key
-const rsa = forge.pki.rsa;
-const publicKey = rsa.setPublicKey(
-  new forge.jsbn.BigInteger(passportData.modulus, 10),
-  new forge.jsbn.BigInteger("10001", 16),
-);
-
-// SHA-256 hash of the eContent
-const md = forge.md.sha256.create();
-md.update(forge.util.binary.raw.encode(new Uint8Array(passportData.eContent)));
-const hashOfEContent = md.digest().getBytes();
-
-console.log('modulus', passportData.modulus);
-console.log('eContent', bytesToBigDecimal(passportData.eContent));
-console.log('signature', bytesToBigDecimal(passportData.encryptedDigest));
-
-// Signature verification
-const signatureBytes = Buffer.from(passportData.encryptedDigest).toString(
-  'binary',
-);
-const valid = publicKey.verify(hashOfEContent, signatureBytes);
-
-if (valid) {
-  console.log('The signature is valid.');
-} else {
-  console.log('The signature is not valid.');
-}
-
-function hash(bytesArray: number[]): number[] {
-  const hash = crypto.createHash('sha256');
-  hash.update(Buffer.from(bytesArray));
-  return Array.from(hash.digest()).map(x => (x < 128 ? x : x - 256));
-}
-function bytesToBigDecimal(arr: number[]): string {
-  let result = BigInt(0);
-  for (let i = 0; i < arr.length; i++) {
-    result = result * BigInt(256) + BigInt(arr[i] & 0xff);
-  }
-  return result.toString();
-}
-
-function hexToDecimal(hex: string): string {
-  return BigInt(`0x${hex}`).toString();
-}
diff --git a/app/types/passportData.ts b/app/types/passportData.ts
deleted file mode 100644
index 2d4d49b92..000000000
--- a/app/types/passportData.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-export type MrzInfo = {
-  compositeCheckDigit: string;
-  dateOfBirth: string;
-  dateOfBirthCheckDigit: string;
-  dateOfExpiry: string;
-  dateOfExpiryCheckDigit: string;
-  documentCode: string;
-  documentNumber: string;
-  documentNumberCheckDigit: string;
-  documentType: number;
-  gender: string;
-  issuingState: string;
-  nationality: string;
-  optionalData1: string;
-  primaryIdentifier: string;
-  secondaryIdentifier: string;
-};
-
-export type DataHash = [number, number[]];
-
-export type PassportData = {
-  mrz: string;
-  signatureAlgorithm: string;
-  pubKey: {modulus?: string, curveName?: string, publicKeyQ?: string};
-  dataGroupHashes: DataHash[];
-  eContent: number[];
-  encryptedDigest: number[];
-};
diff --git a/app/utils/checks.ts b/app/utils/checks.ts
deleted file mode 100644
index e644c50a8..000000000
--- a/app/utils/checks.ts
+++ /dev/null
@@ -1,23 +0,0 @@
-export function checkInputs(
-  passportNumber: string,
-  dateOfBirth: string,
-  dateOfExpiry: string,
-): boolean {
-  if (passportNumber.length !== 9) {
-    throw new Error('Passport number must be 9 characters long');
-  }
-  if (dateOfBirth.length !== 6) {
-    throw new Error('Date of birth must be 6 characters long');
-  }
-  if (dateOfExpiry.length !== 6) {
-    throw new Error('Date of expiry must be 6 characters long');
-  }
-  return true;
-}
-
-export function getFirstName(mrz: string): string {
-  const names = mrz.split("<<");
-  const firstName = names[1].split("<")[0].trim();
-  const capitalized = firstName.charAt(0) + firstName.slice(1).toLowerCase();
-  return capitalized || "Unknown";
-}
\ No newline at end of file
diff --git a/app/utils/computeEContent.ts b/app/utils/computeEContent.ts
deleted file mode 100644
index 59623d8b5..000000000
--- a/app/utils/computeEContent.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-import {PassportData} from '../types/passportData';
-import {
-  arraysAreEqual,
-  assembleEContent,
-  assembleMrz,
-  findTimeOfSignature,
-  formatAndConcatenateDataHashes,
-  formatMrz,
-} from './utils';
-import {sha256} from 'js-sha256';
-
-// hash logic here because the one in utils.ts only works with node
-export function hash(bytesArray: number[]) {
-  let unsignedBytesArray = bytesArray.map(toUnsignedByte);
-  let hash = sha256(unsignedBytesArray);
-  return hexToSignedBytes(hash);
-}
-
-export function hexToSignedBytes(hexString: string) {
-  let bytes = [];
-  for (let i = 0; i < hexString.length - 1; i += 2) {
-    let byte = parseInt(hexString.substr(i, 2), 16);
-    bytes.push(byte >= 128 ? byte - 256 : byte);
-  }
-  return bytes;
-}
-
-export function toUnsignedByte(signedByte: number) {
-  return signedByte < 0 ? signedByte + 256 : signedByte;
-}
diff --git a/app/utils/utils.ts b/app/utils/utils.ts
index 109194455..b9e92499f 100644
--- a/app/utils/utils.ts
+++ b/app/utils/utils.ts
@@ -1,200 +1,8 @@
-import {DataHash, MrzInfo, PassportData} from '../types/passportData';
-
-export function toUnsigned(byte: number) {
-  return byte & 0xff;
-}
-
-export function arraysAreEqual(array1: number[], array2: number[]) {
-  return (
-    array1.length === array2.length &&
-    array1.every((value, index) => value === array2[index])
-  );
-}
-
-export function toSigned(byte: number) {
-  return byte > 127 ? byte - 256 : byte;
-}
-
-export function dataHashesObjToArray(dataHashes: {
-  [key: string]: number[];
-}): DataHash[] {
-  return Object.keys(dataHashes)
-    .map(key => {
-      const dataHash = dataHashes[key as keyof typeof dataHashes];
-      return [Number(key), dataHash];
-    })
-    .sort((a, b) => (a[0] as number) - (b[0] as number)) as DataHash[];
-}
-
-export function assembleMrz(mrzInfo: MrzInfo) {
-  return (
-    mrzInfo.documentCode +
-    '<' +
-    mrzInfo.issuingState +
-    mrzInfo.primaryIdentifier +
-    '<<' +
-    mrzInfo.secondaryIdentifier +
-    mrzInfo.documentNumber +
-    mrzInfo.documentNumberCheckDigit +
-    mrzInfo.nationality +
-    mrzInfo.dateOfBirth +
-    mrzInfo.dateOfBirthCheckDigit +
-    mrzInfo.gender.substring(0, 1) +
-    mrzInfo.dateOfExpiry +
-    mrzInfo.dateOfExpiryCheckDigit +
-    mrzInfo.optionalData1 +
-    mrzInfo.compositeCheckDigit
-  );
-}
-
-export function formatMrz(mrz: string) {
-  const mrzCharcodes = [...mrz].map(char => char.charCodeAt(0));
-
-  // console.log('mrzCharcodes:', mrzCharcodes);
-
-  mrzCharcodes.unshift(88); // the length of the mrz data
-  mrzCharcodes.unshift(95, 31); // the MRZ_INFO_TAG
-  mrzCharcodes.unshift(91); // the new length of the whole array
-  mrzCharcodes.unshift(97); // the tag for DG1
-
-  // console.log('mrzCharcodes with tags:', mrzCharcodes);
-
-  return mrzCharcodes;
-}
-
-// Example: [49, 15, 23, 13, 49, 57, 49, 50, 49, 54, 49, 55, 50, 50, 51, 56, 90]
-// Is "191216172238Z" - 16th December 2019, 17:22:38 UTC
-export function findTimeOfSignature(eContentDecomposed: any) {
-  const timeElement: any = eContentDecomposed.elements.find(
-    (element: any) => element.elements[0].identifier === '1.2.840.113549.1.9.5',
-  );
-
-  if (!timeElement) {
-    throw new Error('No time element found in eContentDecomposed');
-  }
-
-  const timeFound = timeElement.elements[1].elements[0].time;
-
-  // Adding the 4 bytes of the ASN.1 tag and length
-  // 49 : SET, 15 : LGT, 23 : UTCTIME, 13 : LGT
-  timeFound.unshift(...[49, 15, 23, 13]);
-
-  return timeFound;
-}
-
-export function parsePubKeyString(pubKeyString: string) {
-  const modulusMatch = pubKeyString.match(/modulus: ([\w\d]+)\s*public/);
-  const publicExponentMatch = pubKeyString.match(/public exponent: (\w+)/);
-
-  const modulus = modulusMatch ? modulusMatch[1] : null;
-  const exponent = publicExponentMatch ? publicExponentMatch[1] : null;
-
-  // console.log('Modulus:', modulus);
-  // console.log('Public Exponent:', exponent);
-
-  if (!modulus || !exponent) {
-    throw new Error('Could not parse public key string');
-  }
-
-  return {
-    modulus,
-    exponent,
-  };
-}
-
-export function formatAndConcatenateDataHashes(
-  mrzHash: number[],
-  dataHashes: DataHash[],
-) {
-  // Let's replace the first array with the MRZ hash
-  dataHashes.shift();
-  dataHashes.unshift([1, mrzHash]);
-
-  let concat: number[] = []
-
-  // Starting sequence. Should be the same for everybody, but not sure
-  concat.push(...[
-    48, -126, 1, 37, 2, 1, 0, 48, 11, 6, 9, 96, -122, 72, 1, 101, 3, 4, 2, 1,
-    48, -126, 1, 17,
-  ])
-
-  for(const dataHash of dataHashes) {
-    concat.push(...[48, 37, 2, 1, dataHash[0], 4, 32, ...dataHash[1]])
-  }
-
-  return concat;
-}
-
-export function assembleEContent(
-  messageDigest: number[],
-  timeOfSignature: number[],
-) {
-  const constructedEContent = [];
-
-  // Detailed description is in private file r&d.ts for now
-  // First, the tag and length, assumed to be always the same
-  constructedEContent.push(...[49, 102]);
-
-  // 1.2.840.113549.1.9.3 is RFC_3369_CONTENT_TYPE_OID
-  constructedEContent.push(
-    ...[48, 21, 6, 9, 42, -122, 72, -122, -9, 13, 1, 9, 3],
-  );
-  // 2.23.136.1.1.1 is ldsSecurityObject
-  constructedEContent.push(...[49, 8, 6, 6, 103, -127, 8, 1, 1, 1]);
-
-  // 1.2.840.113549.1.9.5 is signing-time
-  constructedEContent.push(
-    ...[48, 28, 6, 9, 42, -122, 72, -122, -9, 13, 1, 9, 5],
-  );
-  // time of the signature
-  constructedEContent.push(...timeOfSignature);
-  // 1.2.840.113549.1.9.4 is RFC_3369_MESSAGE_DIGEST_OID
-  constructedEContent.push(
-    ...[48, 47, 6, 9, 42, -122, 72, -122, -9, 13, 1, 9, 4],
-  );
-  // TAG and length of the message digest
-  constructedEContent.push(...[49, 34, 4, 32]);
-
-  constructedEContent.push(...messageDigest);
-  return constructedEContent;
-}
-
-export const toBinaryString = (byte: any) => {
-  const binary = (parseInt(byte, 10) & 0xFF).toString(2).padStart(8, '0');
-  return binary;
-};
-
-export function splitToWords(
-  number: bigint,
-  wordsize: bigint,
-  numberElement: bigint
-) {
-  let t = number
-  const words: string[] = []
-  for (let i = BigInt(0); i < numberElement; ++i) {
-    const baseTwo = BigInt(2)
-
-    words.push(`${t % BigInt(Math.pow(Number(baseTwo), Number(wordsize)))}`)
-    t = BigInt(t / BigInt(Math.pow(Number(BigInt(2)), Number(wordsize))))
-  }
-  if (!(t == BigInt(0))) {
-    throw `Number ${number} does not fit in ${(
-      wordsize * numberElement
-    ).toString()} bits`
-  }
-  return words
-}
-
-export function bytesToBigDecimal(arr: number[]): string {
-  let result = BigInt(0);
-  for (let i = 0; i < arr.length; i++) {
-    result = result * BigInt(256) + BigInt(arr[i] & 0xff);
-  }
-  return result.toString();
-}
-
-export function hexToDecimal(hex: string): string {
-  return BigInt(`0x${hex}`).toString();
+export function getFirstName(mrz: string): string {
+  const names = mrz.split("<<");
+  const firstName = names[1].split("<")[0].trim();
+  const capitalized = firstName.charAt(0) + firstName.slice(1).toLowerCase();
+  return capitalized || "Unknown";
 }
 
 export function formatDuration(durationInMs: number) {
diff --git a/app/yarn.lock b/app/yarn.lock
index d93f84246..c47456fcb 100644
--- a/app/yarn.lock
+++ b/app/yarn.lock
@@ -3604,6 +3604,17 @@ babel-plugin-jest-hoist@^29.5.0:
     "@types/babel__core" "^7.1.14"
     "@types/babel__traverse" "^7.0.6"
 
+babel-plugin-module-resolver@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-module-resolver/-/babel-plugin-module-resolver-5.0.0.tgz#2b7fc176bd55da25f516abf96015617b4f70fc73"
+  integrity sha512-g0u+/ChLSJ5+PzYwLwP8Rp8Rcfowz58TJNCe+L/ui4rpzE/mg//JVX0EWBUYoxaextqnwuGHzfGp2hh0PPV25Q==
+  dependencies:
+    find-babel-config "^2.0.0"
+    glob "^8.0.3"
+    pkg-up "^3.1.0"
+    reselect "^4.1.7"
+    resolve "^1.22.1"
+
 babel-plugin-polyfill-corejs2@^0.4.4:
   version "0.4.5"
   resolved "https://registry.yarnpkg.com/babel-plugin-polyfill-corejs2/-/babel-plugin-polyfill-corejs2-0.4.5.tgz#8097b4cb4af5b64a1d11332b6fb72ef5e64a054c"
@@ -3767,6 +3778,13 @@ brace-expansion@^1.1.7:
     balanced-match "^1.0.0"
     concat-map "0.0.1"
 
+brace-expansion@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-2.0.1.tgz#1edc459e0f0c548486ecf9fc99f2221364b9a0ae"
+  integrity sha512-XnAIvQ8eM+kC6aULx6wuQiwVsnzsi9d3WxzV3FpWTGA19F621kwdbsAcFKXgKUHZWsy+mY6iL1sHTxWEFCytDA==
+  dependencies:
+    balanced-match "^1.0.0"
+
 braces@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/braces/-/braces-3.0.2.tgz#3454e1a462ee8d599e236df336cd9ea4f8afe107"
@@ -4829,6 +4847,14 @@ finalhandler@1.2.0:
     statuses "2.0.1"
     unpipe "~1.0.0"
 
+find-babel-config@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/find-babel-config/-/find-babel-config-2.0.0.tgz#a8216f825415a839d0f23f4d18338a1cc966f701"
+  integrity sha512-dOKT7jvF3hGzlW60Gc3ONox/0rRZ/tz7WCil0bqA1In/3I8f1BctpXahRnEKDySZqci7u+dqq93sZST9fOJpFw==
+  dependencies:
+    json5 "^2.1.1"
+    path-exists "^4.0.0"
+
 find-cache-dir@^2.0.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/find-cache-dir/-/find-cache-dir-2.1.0.tgz#8d0f94cd13fe43c6c7c261a0d86115ca918c05f7"
@@ -4930,6 +4956,11 @@ function-bind@^1.1.1:
   resolved "https://registry.yarnpkg.com/function-bind/-/function-bind-1.1.1.tgz#a56899d3ea3c9bab874bb9773b7c5ede92f4895d"
   integrity sha512-yIovAzMX49sF8Yl58fSCWJ5svSLuaibPxXQJFLmBObTuCr0Mf1KiPopGM9NiFjiYBCbfaa2Fh6breQ6ANVTI0A==
 
+function-bind@^1.1.2:
+  version "1.1.2"
+  resolved "https://registry.yarnpkg.com/function-bind/-/function-bind-1.1.2.tgz#2c02d864d97f3ea6c8830c464cbd11ab6eab7a1c"
+  integrity sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==
+
 function.prototype.name@^1.1.5:
   version "1.1.5"
   resolved "https://registry.yarnpkg.com/function.prototype.name/-/function.prototype.name-1.1.5.tgz#cce0505fe1ffb80503e6f9e46cc64e46a12a9621"
@@ -5009,6 +5040,17 @@ glob@^7.1.3, glob@^7.1.4:
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
+glob@^8.0.3:
+  version "8.1.0"
+  resolved "https://registry.yarnpkg.com/glob/-/glob-8.1.0.tgz#d388f656593ef708ee3e34640fdfb99a9fd1c33e"
+  integrity sha512-r8hpEjiQEYlF2QU0df3dS+nxxSIreXQS1qRhMJM0Q5NDdR386C7jb7Hwwod8Fgiuex+k0GFjgft18yvxm5XoCQ==
+  dependencies:
+    fs.realpath "^1.0.0"
+    inflight "^1.0.4"
+    inherits "2"
+    minimatch "^5.0.1"
+    once "^1.3.0"
+
 globals@^11.1.0:
   version "11.12.0"
   resolved "https://registry.yarnpkg.com/globals/-/globals-11.12.0.tgz#ab8795338868a0babd8525758018c2a7eb95c42e"
@@ -5103,6 +5145,13 @@ has@^1.0.3:
   dependencies:
     function-bind "^1.1.1"
 
+hasown@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/hasown/-/hasown-2.0.0.tgz#f4c513d454a57b7c7e1650778de226b11700546c"
+  integrity sha512-vUptKVTpIJhcczKBbgnS+RtcuYMB8+oNzPK2/Hp3hanz8JmpATdmmgLgSaadVREkDm+e2giHwY3ZRkyjSIDDFA==
+  dependencies:
+    function-bind "^1.1.2"
+
 hermes-estree@0.12.0:
   version "0.12.0"
   resolved "https://registry.yarnpkg.com/hermes-estree/-/hermes-estree-0.12.0.tgz#8a289f9aee854854422345e6995a48613bac2ca8"
@@ -5299,6 +5348,13 @@ is-core-module@^2.11.0, is-core-module@^2.9.0:
   dependencies:
     has "^1.0.3"
 
+is-core-module@^2.13.0:
+  version "2.13.1"
+  resolved "https://registry.yarnpkg.com/is-core-module/-/is-core-module-2.13.1.tgz#ad0d7532c6fea9da1ebdc82742d74525c6273384"
+  integrity sha512-hHrIjvZsftOsvKSn2TRYl63zvxsgE0K+0mYMoH6gD4omR5IWB2KynivBQczo3+wF1cCkjzvptnI9Q0sPU66ilw==
+  dependencies:
+    hasown "^2.0.0"
+
 is-date-object@^1.0.1:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/is-date-object/-/is-date-object-1.0.5.tgz#0841d5536e724c25597bf6ea62e1bd38298df31f"
@@ -5977,7 +6033,7 @@ json-stable-stringify-without-jsonify@^1.0.1:
   resolved "https://registry.yarnpkg.com/json-stable-stringify-without-jsonify/-/json-stable-stringify-without-jsonify-1.0.1.tgz#9db7b59496ad3f3cfef30a75142d2d930ad72651"
   integrity sha512-Bdboy+l7tA3OGW6FjyFHWkP5LuByj1Tk33Ljyq0axyzdk9//JSi2u3fP1QSmd1KNwq6VOKYGlAu87CisVir6Pw==
 
-json5@^2.2.2:
+json5@^2.1.1, json5@^2.2.2:
   version "2.2.3"
   resolved "https://registry.yarnpkg.com/json5/-/json5-2.2.3.tgz#78cd6f1a19bdc12b73db5ad0c61efd66c1e29283"
   integrity sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg==
@@ -6479,6 +6535,13 @@ minimatch@^3.0.2, minimatch@^3.0.4, minimatch@^3.0.5, minimatch@^3.1.1, minimatc
   dependencies:
     brace-expansion "^1.1.7"
 
+minimatch@^5.0.1:
+  version "5.1.6"
+  resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-5.1.6.tgz#1cfcb8cf5522ea69952cd2af95ae09477f122a96"
+  integrity sha512-lKwV/1brpG6mBUFHtb7NUmtABCb2WZZmm2wNiOA5hAb8VdCS4B3dtMWyvcoViccwAW/COERjXLt0zP1zXUN26g==
+  dependencies:
+    brace-expansion "^2.0.1"
+
 minimist@^1.2.6:
   version "1.2.8"
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.8.tgz#c1a464e7693302e082a075cee0c057741ac4772c"
@@ -6870,6 +6933,13 @@ pkg-dir@^4.2.0:
   dependencies:
     find-up "^4.0.0"
 
+pkg-up@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/pkg-up/-/pkg-up-3.1.0.tgz#100ec235cc150e4fd42519412596a28512a0def5"
+  integrity sha512-nDywThFk1i4BQK4twPQ6TA4RT8bDY96yeuCVBWL3ePARCiEKDRSrNGbFIgUJpLp+XeIR65v8ra7WuJOFUBtkMA==
+  dependencies:
+    find-up "^3.0.0"
+
 prelude-ls@^1.2.1:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.2.1.tgz#debc6489d7a6e6b0e7611888cec880337d316396"
@@ -7248,6 +7318,11 @@ require-main-filename@^2.0.0:
   resolved "https://registry.yarnpkg.com/require-main-filename/-/require-main-filename-2.0.0.tgz#d0b329ecc7cc0f61649f62215be69af54aa8989b"
   integrity sha512-NKN5kMDylKuldxYLSUfrbo5Tuzh4hd+2E8NPPX02mZtn1VuREQToYe/ZdlJy+J3uCpfaiGF05e7B8W0iXbQHmg==
 
+reselect@^4.1.7:
+  version "4.1.8"
+  resolved "https://registry.yarnpkg.com/reselect/-/reselect-4.1.8.tgz#3f5dc671ea168dccdeb3e141236f69f02eaec524"
+  integrity sha512-ab9EmR80F/zQTMNeneUr4cv+jSwPJgIlvEmVwLerwrWVbpLlBuls9XHzIeTFy4cegU2NHBp3va0LKOzU5qFEYQ==
+
 resolve-cwd@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/resolve-cwd/-/resolve-cwd-3.0.0.tgz#0f0075f1bb2544766cf73ba6a6e2adfebcb13f2d"
@@ -7284,6 +7359,15 @@ resolve@^1.14.2, resolve@^1.20.0:
     path-parse "^1.0.7"
     supports-preserve-symlinks-flag "^1.0.0"
 
+resolve@^1.22.1:
+  version "1.22.8"
+  resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.22.8.tgz#b6c87a9f2aa06dfab52e3d70ac8cde321fa5a48d"
+  integrity sha512-oKWePCxqpd6FlLvGV1VU0x7bkPmmCNolxzjMf4NczoDnQcIWrAF+cPtZn5i6n+RfD2d9i0tzpKnG6Yk168yIyw==
+  dependencies:
+    is-core-module "^2.13.0"
+    path-parse "^1.0.7"
+    supports-preserve-symlinks-flag "^1.0.0"
+
 resolve@^2.0.0-next.4:
   version "2.0.0-next.4"
   resolved "https://registry.yarnpkg.com/resolve/-/resolve-2.0.0-next.4.tgz#3d37a113d6429f496ec4752d2a2e58efb1fd4660"
diff --git a/circuits/scripts/mrzToSig.ts b/circuits/scripts/mrzToSig.ts
index 48d1d684f..32ccb7347 100644
--- a/circuits/scripts/mrzToSig.ts
+++ b/circuits/scripts/mrzToSig.ts
@@ -1,20 +1,13 @@
 import * as crypto from 'crypto';
 import {
   arraysAreEqual,
-  dataHashesObjToArray,
   formatMrz,
-  assembleMrz,
-  findTimeOfSignature,
-  parsePubKeyString,
   formatAndConcatenateDataHashes,
-  assembleEContent,
-  hexToDecimal,
   bytesToBigDecimal,
-} from '../utils/utils';
+} from '../../common/src/utils/utils';
 import * as forge from 'node-forge';
-import passportData from '../inputs/passportData_florent.json';
-import {DataHash} from '../utils/types';
-import { genSampleData } from '../utils/sampleData';
+import passportData from '../../common/inputs/passportData.json';
+import {DataHash} from '../../common/src/utils/types';
 
 // This script tests the whole flow from MRZ to signature
 // The passportData is imported from passportData.json written by the server
@@ -54,7 +47,7 @@ console.log(
 // Create the public key
 const rsa = forge.pki.rsa;
 const publicKey = rsa.setPublicKey(
-  new forge.jsbn.BigInteger(passportData.modulus, 10),
+  new forge.jsbn.BigInteger(passportData.pubKey.modulus, 10),
   new forge.jsbn.BigInteger("10001", 16),
 );
 
@@ -63,7 +56,7 @@ const md = forge.md.sha256.create();
 md.update(forge.util.binary.raw.encode(new Uint8Array(passportData.eContent)));
 const hashOfEContent = md.digest().getBytes();
 
-console.log('modulus', passportData.modulus);
+console.log('modulus', passportData.pubKey.modulus);
 console.log('eContent', bytesToBigDecimal(passportData.eContent));
 console.log('signature', bytesToBigDecimal(passportData.encryptedDigest));
 
diff --git a/circuits/test/passport.test.ts b/circuits/test/passport.test.ts
index 52dadf40c..4c018d252 100644
--- a/circuits/test/passport.test.ts
+++ b/circuits/test/passport.test.ts
@@ -1,11 +1,11 @@
 import { describe } from 'mocha'
 import chai, { assert, expect } from 'chai'
 import chaiAsPromised from 'chai-as-promised'
-import { arraysAreEqual, bytesToBigDecimal, formatAndConcatenateDataHashes, formatMrz, splitToWords } from '../utils/utils'
+import { hash, toUnsignedByte, arraysAreEqual, bytesToBigDecimal, formatAndConcatenateDataHashes, formatMrz, splitToWords } from '../../common/src/utils/utils'
 import { groth16 } from 'snarkjs'
-import { hash, toUnsignedByte } from '../utils/computeEContent'
-import { DataHash, PassportData } from '../utils/types'
-import { genSampleData } from '../utils/sampleData'
+import { DataHash, PassportData } from '../../common/src/utils/types'
+import { getPassportData } from '../../common/src/utils/passportData'
+import { attributeToPosition } from '../../common/src/constants/constants'
 const fs = require('fs');
 
 chai.use(chaiAsPromised)
@@ -17,15 +17,7 @@ describe('Circuit tests', function () {
   let inputs: any;
 
   this.beforeAll(async () => {
-    if (fs.existsSync('inputs/passportData.json')) {
-      passportData = require('../inputs/passportData.json');
-    } else {
-      passportData = (await genSampleData()) as PassportData;
-      if (!fs.existsSync("inputs/")) {
-        fs.mkdirSync("inputs/");
-      }
-      fs.writeFileSync('inputs/passportData.json', JSON.stringify(passportData));
-    }
+    const passportData = getPassportData();
 
     const formattedMrz = formatMrz(passportData.mrz);
     const mrzHash = hash(formatMrz(passportData.mrz));
@@ -51,7 +43,7 @@ describe('Circuit tests', function () {
       dataHashes: concatenatedDataHashes.map(toUnsignedByte).map(byte => String(byte)),
       eContentBytes: passportData.eContent.map(toUnsignedByte).map(byte => String(byte)),
       pubkey: splitToWords(
-        BigInt(passportData.modulus),
+        BigInt(passportData.pubKey.modulus),
         BigInt(64),
         BigInt(32)
       ),
@@ -60,7 +52,7 @@ describe('Circuit tests', function () {
         BigInt(64),
         BigInt(32)
       ),
-      address: "0x9D392187c08fc28A86e1354aD63C70897165b982",
+      address: "0x70997970c51812dc3a010c7d01b50e0d17dc79c8",
     }
     
   })
@@ -133,16 +125,6 @@ describe('Circuit tests', function () {
   })
 
   describe('Selective disclosure', function() {
-    const attributeToPosition = {
-      issuing_state: [2, 4],
-      name: [5, 43],
-      passport_number: [44, 52],
-      nationality: [54, 56],
-      date_of_birth: [57, 62],
-      gender: [64, 64],
-      expiry_date: [65, 70],
-    }
-
     const attributeCombinations = [
       ['issuing_state', 'name'],
       ['passport_number', 'nationality', 'date_of_birth'],
@@ -150,7 +132,7 @@ describe('Circuit tests', function () {
     ];
 
     attributeCombinations.forEach(combination => {
-      it.only(`Disclosing ${combination.join(", ")}`, async function () {
+      it(`Disclosing ${combination.join(", ")}`, async function () {
         const attributeToReveal = Object.keys(attributeToPosition).reduce((acc, attribute) => {
           acc[attribute] = combination.includes(attribute);
           return acc;
@@ -224,21 +206,3 @@ describe('Circuit tests', function () {
 })
 
 
-
-// [
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', 'F',    'R',
-//   'A',    '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
-//   '\x00', '\x00', '\x00', '\x00'
-// ]
-
-// P<FRADUPONT<<ALPHONSE<HUGUES<ALBERT<<<<<<<<<24HB818324FRA0402111M3111115<<<<<<<<<<<<<<02
diff --git a/circuits/utils/checks.ts b/circuits/utils/checks.ts
deleted file mode 100644
index 9074d13de..000000000
--- a/circuits/utils/checks.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-export function checkInputs(
-  passportNumber: string,
-  dateOfBirth: string,
-  dateOfExpiry: string,
-): boolean {
-  if (passportNumber.length !== 9) {
-    throw new Error('Passport number must be 9 characters long');
-  }
-  if (dateOfBirth.length !== 6) {
-    throw new Error('Date of birth must be 6 characters long');
-  }
-  if (dateOfExpiry.length !== 6) {
-    throw new Error('Date of expiry must be 6 characters long');
-  }
-  return true;
-}
-
-export function getFirstName(mrzInfo: any): string {
-  const firstName = mrzInfo.secondaryIdentifier.split('<')[0];
-  return firstName.charAt(0).toUpperCase() + firstName.slice(1).toLowerCase();
-}
diff --git a/circuits/utils/computeEContent.ts b/circuits/utils/computeEContent.ts
deleted file mode 100644
index ed33cc5ea..000000000
--- a/circuits/utils/computeEContent.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-import {sha256} from 'js-sha256';
-
-// hash logic here because the one in utils.ts only works with node
-export function hash(bytesArray: number[]) {
-  let unsignedBytesArray = bytesArray.map(toUnsignedByte);
-  let hash = sha256(unsignedBytesArray);
-  return hexToSignedBytes(hash);
-}
-
-export function hexToSignedBytes(hexString: string): number[] {
-  let bytes = [];
-  for (let i = 0; i < hexString.length - 1; i += 2) {
-    let byte = parseInt(hexString.substr(i, 2), 16);
-    bytes.push(byte >= 128 ? byte - 256 : byte);
-  }
-  return bytes;
-}
-
-export function toUnsignedByte(signedByte: number) {
-  return signedByte < 0 ? signedByte + 256 : signedByte;
-}
diff --git a/circuits/utils/types.ts b/circuits/utils/types.ts
deleted file mode 100644
index 53c9c0414..000000000
--- a/circuits/utils/types.ts
+++ /dev/null
@@ -1,27 +0,0 @@
-export type MrzInfo = {
-  compositeCheckDigit: string;
-  dateOfBirth: string;
-  dateOfBirthCheckDigit: string;
-  dateOfExpiry: string;
-  dateOfExpiryCheckDigit: string;
-  documentCode: string;
-  documentNumber: string;
-  documentNumberCheckDigit: string;
-  documentType: number;
-  gender: string;
-  issuingState: string;
-  nationality: string;
-  optionalData1: string;
-  primaryIdentifier: string;
-  secondaryIdentifier: string;
-};
-
-export type DataHash = [number, number[]];
-
-export type PassportData = {
-  mrz: string;
-  modulus: string;
-  dataGroupHashes: DataHash[];
-  eContent: number[];
-  encryptedDigest: number[];
-};
diff --git a/common/.gitignore b/common/.gitignore
new file mode 100644
index 000000000..281d0e41e
--- /dev/null
+++ b/common/.gitignore
@@ -0,0 +1,2 @@
+inputs
+node_modules/
\ No newline at end of file
diff --git a/common/README.md b/common/README.md
new file mode 100644
index 000000000..218bda03b
--- /dev/null
+++ b/common/README.md
@@ -0,0 +1,3 @@
+# Proof of Passport Commons
+
+Constants and utils used in multiple Proof of Passport subdirectories.
diff --git a/common/package.json b/common/package.json
new file mode 100644
index 000000000..5de125cdf
--- /dev/null
+++ b/common/package.json
@@ -0,0 +1,10 @@
+{
+  "dependencies": {
+    "@babel/runtime": "^7.23.4",
+    "js-sha256": "^0.10.1",
+    "node-forge": "^1.3.1"
+  },
+  "devDependencies": {
+    "@types/node-forge": "^1.3.10"
+  }
+}
diff --git a/common/src/constants/constants.ts b/common/src/constants/constants.ts
new file mode 100644
index 000000000..3f6743445
--- /dev/null
+++ b/common/src/constants/constants.ts
@@ -0,0 +1,9 @@
+export const attributeToPosition = {
+  issuing_state: [2, 4],
+  name: [5, 43],
+  passport_number: [44, 52],
+  nationality: [54, 56],
+  date_of_birth: [57, 62],
+  gender: [64, 64],
+  expiry_date: [65, 70],
+}
\ No newline at end of file
diff --git a/circuits/utils/sampleData.ts b/common/src/utils/passportData.ts
similarity index 60%
rename from circuits/utils/sampleData.ts
rename to common/src/utils/passportData.ts
index 12d5008e9..a9b3854d1 100644
--- a/circuits/utils/sampleData.ts
+++ b/common/src/utils/passportData.ts
@@ -1,7 +1,7 @@
-import { hash } from "./computeEContent";
-import { DataHash } from "./types";
-import { assembleEContent, formatAndConcatenateDataHashes, formatMrz, hexToDecimal } from "./utils";
+import { DataHash, PassportData } from "./types";
+import { hash, assembleEContent, formatAndConcatenateDataHashes, formatMrz, hexToDecimal } from "./utils";
 import * as forge from 'node-forge';
+const fs = require('fs');
 
 const sampleMRZ = "P<FRADUPONT<<ALPHONSE<HUGUES<ALBERT<<<<<<<<<24HB818324FRA0402111M3111115<<<<<<<<<<<<<<02"
 const sampleDataHashes = [
@@ -32,7 +32,7 @@ const sampleDataHashes = [
 ]
 const sampleTimeOfSig = [49, 15, 23, 13, 49, 57, 49, 50, 49, 54, 49, 55, 50, 50, 51, 56, 90]
 
-export async function genSampleData() {
+export function genSampleData(): PassportData {
   const mrzHash = hash(formatMrz(sampleMRZ));
   sampleDataHashes.unshift([1, mrzHash]);
   const concatenatedDataHashes = formatAndConcatenateDataHashes(
@@ -52,24 +52,38 @@ export async function genSampleData() {
   md.update(forge.util.binary.raw.encode(new Uint8Array(eContent)));
 
   const signature = privKey.sign(md)
-  const signatureBytes = Array.from(signature, c => c.charCodeAt(0));
+  const signatureBytes = Array.from(signature, (c: string) => c.charCodeAt(0));
   
   // Signature verification
-  const hashOfEContent = md.digest().getBytes();
-  const publicKey = rsa.setPublicKey(
-    new forge.jsbn.BigInteger(modulus, 16),
-    new forge.jsbn.BigInteger("10001", 16),
-  );
-  const valid = publicKey.verify(hashOfEContent, signature);
-  console.log('valid ?', valid)
+  // const hashOfEContent = md.digest().getBytes();
+  // const publicKey = rsa.setPublicKey(
+  //   new forge.jsbn.BigInteger(modulus, 16),
+  //   new forge.jsbn.BigInteger("10001", 16),
+  // );
+  // const valid = publicKey.verify(hashOfEContent, signature);
+  // console.log('valid ?', valid)
 
   return {
-    "mrz": sampleMRZ,
-    modulus: hexToDecimal(modulus),
-    "dataGroupHashes": sampleDataHashes,
-    "eContent": eContent,
-    "encryptedDigest": signatureBytes,
+    mrz: sampleMRZ,
+    signatureAlgorithm: 'SHA256withRSA', // sha256WithRSAEncryption
+    pubKey: {
+      modulus: hexToDecimal(modulus),
+    },
+    dataGroupHashes: sampleDataHashes as DataHash[],
+    eContent: eContent,
+    encryptedDigest: signatureBytes,
   }
 }
 
-
+export function getPassportData(): PassportData {
+  if (fs.existsSync('../../inputs/passportData.json')) {
+    return require('../../inputs/passportData.json');
+  } else {
+    const sampleData = genSampleData();
+    if (!fs.existsSync('../../inputs/')) {
+      fs.mkdirSync('../../inputs/');
+    }
+    fs.writeFileSync('../../inputs/passportData.json', JSON.stringify(sampleData));
+    return sampleData;
+  }
+}
diff --git a/common/src/utils/types.ts b/common/src/utils/types.ts
new file mode 100644
index 000000000..7fb011bf3
--- /dev/null
+++ b/common/src/utils/types.ts
@@ -0,0 +1,10 @@
+export type DataHash = [number, number[]];
+
+export type PassportData = {
+  mrz: string;
+  signatureAlgorithm: string;
+  pubKey: {modulus?: string, curveName?: string, publicKeyQ?: string};
+  dataGroupHashes: DataHash[];
+  eContent: number[];
+  encryptedDigest: number[];
+};
diff --git a/circuits/utils/utils.ts b/common/src/utils/utils.ts
similarity index 77%
rename from circuits/utils/utils.ts
rename to common/src/utils/utils.ts
index f5613885c..a7a4de71f 100644
--- a/circuits/utils/utils.ts
+++ b/common/src/utils/utils.ts
@@ -1,19 +1,5 @@
-import {DataHash, MrzInfo, PassportData} from './types';
-
-export function toUnsigned(byte: number) {
-  return byte & 0xff;
-}
-
-export function arraysAreEqual(array1: number[], array2: number[]) {
-  return (
-    array1.length === array2.length &&
-    array1.every((value, index) => value === array2[index])
-  );
-}
-
-export function toSigned(byte: number) {
-  return byte > 127 ? byte - 256 : byte;
-}
+import { DataHash } from './types';
+import {sha256} from 'js-sha256';
 
 export function dataHashesObjToArray(dataHashes: {
   [key: string]: number[];
@@ -26,27 +12,6 @@ export function dataHashesObjToArray(dataHashes: {
     .sort((a, b) => (a[0] as number) - (b[0] as number)) as DataHash[];
 }
 
-export function assembleMrz(mrzInfo: MrzInfo) {
-  return (
-    mrzInfo.documentCode +
-    '<' +
-    mrzInfo.issuingState +
-    mrzInfo.primaryIdentifier +
-    '<<' +
-    mrzInfo.secondaryIdentifier +
-    mrzInfo.documentNumber +
-    mrzInfo.documentNumberCheckDigit +
-    mrzInfo.nationality +
-    mrzInfo.dateOfBirth +
-    mrzInfo.dateOfBirthCheckDigit +
-    mrzInfo.gender.substring(0, 1) +
-    mrzInfo.dateOfExpiry +
-    mrzInfo.dateOfExpiryCheckDigit +
-    mrzInfo.optionalData1 +
-    mrzInfo.compositeCheckDigit
-  );
-}
-
 export function formatMrz(mrz: string) {
   const mrzCharcodes = [...mrz].map(char => char.charCodeAt(0));
 
@@ -62,26 +27,6 @@ export function formatMrz(mrz: string) {
   return mrzCharcodes;
 }
 
-// Example: [49, 15, 23, 13, 49, 57, 49, 50, 49, 54, 49, 55, 50, 50, 51, 56, 90]
-// Is "191216172238Z" - 16th December 2019, 17:22:38 UTC
-export function findTimeOfSignature(eContentDecomposed: any) {
-  const timeElement: any = eContentDecomposed.elements.find(
-    (element: any) => element.elements[0].identifier === '1.2.840.113549.1.9.5',
-  );
-
-  if (!timeElement) {
-    throw new Error('No time element found in eContentDecomposed');
-  }
-
-  const timeFound = timeElement.elements[1].elements[0].time;
-
-  // Adding the 4 bytes of the ASN.1 tag and length
-  // 49 : SET, 15 : LGT, 23 : UTCTIME, 13 : LGT
-  timeFound.unshift(...[49, 15, 23, 13]);
-
-  return timeFound;
-}
-
 export function parsePubKeyString(pubKeyString: string) {
   const modulusMatch = pubKeyString.match(/modulus: ([\w\d]+)\s*public/);
   const publicExponentMatch = pubKeyString.match(/public exponent: (\w+)/);
@@ -160,6 +105,38 @@ export function assembleEContent(
   return constructedEContent;
 }
 
+export function checkInputs(
+  passportNumber: string,
+  dateOfBirth: string,
+  dateOfExpiry: string,
+): boolean {
+  if (passportNumber.length !== 9) {
+    throw new Error('Passport number must be 9 characters long');
+  }
+  if (dateOfBirth.length !== 6) {
+    throw new Error('Date of birth must be 6 characters long');
+  }
+  if (dateOfExpiry.length !== 6) {
+    throw new Error('Date of expiry must be 6 characters long');
+  }
+  return true;
+}
+
+export function toUnsigned(byte: number) {
+  return byte & 0xff;
+}
+
+export function arraysAreEqual(array1: number[], array2: number[]) {
+  return (
+    array1.length === array2.length &&
+    array1.every((value, index) => value === array2[index])
+  );
+}
+
+export function toSigned(byte: number) {
+  return byte > 127 ? byte - 256 : byte;
+}
+
 export const toBinaryString = (byte: any) => {
   const binary = (parseInt(byte, 10) & 0xFF).toString(2).padStart(8, '0');
   return binary;
@@ -196,4 +173,24 @@ export function bytesToBigDecimal(arr: number[]): string {
 
 export function hexToDecimal(hex: string): string {
   return BigInt(`0x${hex}`).toString();
-}
\ No newline at end of file
+}
+
+// hash logic here because the one in utils.ts only works with node
+export function hash(bytesArray: number[]) {
+  let unsignedBytesArray = bytesArray.map(toUnsignedByte);
+  let hash = sha256(unsignedBytesArray);
+  return hexToSignedBytes(hash);
+}
+
+export function hexToSignedBytes(hexString: string): number[] {
+  let bytes = [];
+  for (let i = 0; i < hexString.length - 1; i += 2) {
+    let byte = parseInt(hexString.substr(i, 2), 16);
+    bytes.push(byte >= 128 ? byte - 256 : byte);
+  }
+  return bytes;
+}
+
+export function toUnsignedByte(signedByte: number) {
+  return signedByte < 0 ? signedByte + 256 : signedByte;
+}
diff --git a/common/tsconfig.json b/common/tsconfig.json
new file mode 100644
index 000000000..a05d480d5
--- /dev/null
+++ b/common/tsconfig.json
@@ -0,0 +1,8 @@
+{
+  "compilerOptions": {
+    "resolveJsonModule": true,
+    "esModuleInterop": true,
+    "target": "ES2015",
+    "moduleResolution": "node"
+  }
+}
\ No newline at end of file
diff --git a/common/yarn.lock b/common/yarn.lock
new file mode 100644
index 000000000..64ca82b09
--- /dev/null
+++ b/common/yarn.lock
@@ -0,0 +1,44 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+"@babel/runtime@^7.23.4":
+  version "7.23.4"
+  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.23.4.tgz#36fa1d2b36db873d25ec631dcc4923fdc1cf2e2e"
+  integrity sha512-2Yv65nlWnWlSpe3fXEyX5i7fx5kIKo4Qbcj+hMO0odwaneFjfXw5fdum+4yL20O0QiaHpia0cYQ9xpNMqrBwHg==
+  dependencies:
+    regenerator-runtime "^0.14.0"
+
+"@types/node-forge@^1.3.10":
+  version "1.3.10"
+  resolved "https://registry.npmjs.org/@types/node-forge/-/node-forge-1.3.10.tgz"
+  integrity sha512-y6PJDYN4xYBxwd22l+OVH35N+1fCYWiuC3aiP2SlXVE6Lo7SS+rSx9r89hLxrP4pn6n1lBGhHJ12pj3F3Mpttw==
+  dependencies:
+    "@types/node" "*"
+
+"@types/node@*":
+  version "20.10.0"
+  resolved "https://registry.npmjs.org/@types/node/-/node-20.10.0.tgz"
+  integrity sha512-D0WfRmU9TQ8I9PFx9Yc+EBHw+vSpIub4IDvQivcp26PtPrdMGAq5SDcpXEo/epqa/DXotVpekHiLNTg3iaKXBQ==
+  dependencies:
+    undici-types "~5.26.4"
+
+js-sha256@^0.10.1:
+  version "0.10.1"
+  resolved "https://registry.npmjs.org/js-sha256/-/js-sha256-0.10.1.tgz"
+  integrity sha512-5obBtsz9301ULlsgggLg542s/jqtddfOpV5KJc4hajc9JV8GeY2gZHSVpYBn4nWqAUTJ9v+xwtbJ1mIBgIH5Vw==
+
+node-forge@^1.3.1:
+  version "1.3.1"
+  resolved "https://registry.npmjs.org/node-forge/-/node-forge-1.3.1.tgz"
+  integrity sha512-dPEtOeMvF9VMcYV/1Wb8CPoVAXtp6MKMlcbAt4ddqmGqUJ6fQZFXkNZNkNlfevtNkGtaSoXf/vNNNSvgrdXwtA==
+
+regenerator-runtime@^0.14.0:
+  version "0.14.0"
+  resolved "https://registry.yarnpkg.com/regenerator-runtime/-/regenerator-runtime-0.14.0.tgz#5e19d68eb12d486f797e15a3c6a918f7cec5eb45"
+  integrity sha512-srw17NI0TUWHuGa5CFGGmhfNIeja30WMBfbslPNhf6JrqQlLN5gcrvig1oqPxiVaXb0oW0XRKtH6Nngs5lKCIA==
+
+undici-types@~5.26.4:
+  version "5.26.5"
+  resolved "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz"
+  integrity sha512-JlCMO+ehdEIKqlFxk6IfVoAUVmgz7cU7zD/h9XZ0qzeosSHmUJVOzSQvvYSYWXkFXC+IfLKSIffhv0sVZup6pA==