@stellot/crypto/lib/esm/elGamal/encryption.js

Crypto libraries for front and backend

import { parseBigInt } from "./utils";
import { BigInteger as BigInt } from 'jsbn';
import * as Utils from "./utils";
import DecryptedValue from "./decryptedValue";
import EncryptedValue from "./encryptedValue";
export default class EncryptionElGamal {
    constructor(p, g, y) {
        this.p = parseBigInt(p);
        this.g = parseBigInt(g);
        this.y = parseBigInt(y);
    }
    encrypt(m, k) {
        const tmpKey = k ? Utils.parseBigInt(k) : Utils.getRandomBigInt(BigInt.ONE, this.p.subtract(BigInt.ONE));
        const mBi = new DecryptedValue(m).bi;
        const p = this.p;
        const a = this.g.modPow(tmpKey, p);
        const b = this.y.modPow(tmpKey, p).multiply(mBi).remainder(p);
        return new EncryptedValue(a, b);
    }
}