通过RSA算法对值进行加解密

Question

我编写了一个RSA加解密程序。对于某些数值，解密结果与原始值不匹配。

例如：

327: 解密不错
512：解密有问题

我使用BigInteger.ModPow()进行加密和解密。

using System;
using System.Numerics;

namespace ExperimentsWithCryptographicAlgorithms
{
    class Program
    {
        static void Main(string[] args)
        {
            BigInteger number = new BigInteger(327);

            KeyPair keys = new KeyPair();
            keys.OpenKey = new Key(new BigInteger(5), new BigInteger(493));
            keys.SecurityKey = new Key(new BigInteger(269), new BigInteger(493));

            BigInteger hash = Encrypt(number, keys.OpenKey);
            if (Decrypt(hash, keys.SecurityKey) == number)
            {
                Console.WriteLine("Succesfully encrypted / decrypted!");
            }
            else
            {
                Console.WriteLine("Error in encryption or decryption!");
            }
        }

        static BigInteger Encrypt(BigInteger encryptedValue, Key publicKey)
        {
            return BigInteger.ModPow(encryptedValue, publicKey.FirstPart, publicKey.SecondPart);
        }

        static BigInteger Decrypt(BigInteger decryptedValue, Key securityKey)
        {
            return BigInteger.ModPow(decryptedValue, securityKey.FirstPart, securityKey.SecondPart);
        }
    }

    public struct Key
    {
        public BigInteger FirstPart { get; set; }
        public BigInteger SecondPart { get; set; }

        public Key(BigInteger fPart, BigInteger sPart)
        {
            FirstPart = fPart;
            SecondPart = sPart;
        }
    }

    public struct KeyPair
    {
        public Key OpenKey { get; set; }
        public Key SecurityKey { get; set; }
    }
}

Answer 1

我检查了你的算法，它适用于 -492 到 492 范围内的数字。这似乎是算法的物理限制，因为最后一个算术运算是 securityKey.SecondPart 的模数，这发生了成为 493.

通过RSA算法对值进行加解密

Encrypt and decrypt value by RSA algorithm

c#

rsa