很好的例子如何做到这一点使用PGPCore与BouncyCastle，非常简单的解决方案:https://blog.bitscry.com/2018/07/05/pgp-encryption-and-decryption-in-c/

我尝试了不同的解决方案，但这对我来说是最好的，有些bug，但这是完美的。

using (PGP pgp = new PGP())
{
// Generate keys
pgp.GenerateKey(@"C:\TEMP\keys\public.asc", @"C:\TEMP\keys\private.asc", "email@email.com", "password");
// Encrypt file
pgp.EncryptFile(@"C:\TEMP\keys\content.txt", @"C:\TEMP\keys\content__encrypted.pgp", @"C:\TEMP\keys\public.asc", true, true);
// Encrypt and sign file
pgp.EncryptFileAndSign(@"C:\TEMP\keys\content.txt", @"C:\TEMP\keys\content__encrypted_signed.pgp", @"C:\TEMP\keys\public.asc", @"C:\TEMP\keys\private.asc", "password", true, true);
// Decrypt file
pgp.DecryptFile(@"C:\TEMP\keys\content__encrypted.pgp", @"C:\TEMP\keys\content__decrypted.txt", @"C:\TEMP\keys\private.asc", "password");
// Decrypt signed file
pgp.DecryptFile(@"C:\TEMP\keys\content__encrypted_signed.pgp", @"C:\TEMP\keys\content__decrypted_signed.txt", @"C:\TEMP\keys\private.asc", "password");

// Encrypt stream
using (FileStream inputFileStream = new FileStream(@"C:\TEMP\keys\content.txt", FileMode.Open))
using (Stream outputFileStream = File.Create(@"C:\TEMP\keys\content__encrypted2.pgp"))
using (Stream publicKeyStream = new FileStream(@"C:\TEMP\keys\public.asc", FileMode.Open))
    pgp.EncryptStream(inputFileStream, outputFileStream, publicKeyStream, true, true);

// Decrypt stream
using (FileStream inputFileStream = new FileStream(@"C:\TEMP\keys\content__encrypted2.pgp", FileMode.Open))
using (Stream outputFileStream = File.Create(@"C:\TEMP\keys\content__decrypted2.txt"))
using (Stream privateKeyStream = new FileStream(@"C:\TEMP\keys\private.asc", FileMode.Open))
    pgp.DecryptStream(inputFileStream, outputFileStream, privateKeyStream, "password");
}

我想给你我的贡献，与我的代码AES Rfc2898DeriveBytes(这里的文档)算法，写在c#(。NET框架4)，并且完全适用于有限的平台，如Windows Phone 7.0+的.NET紧凑框架(不是所有平台都支持.NET框架的每一种编码方法!)

我希望这能帮助到任何人!

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

public static class Crypto
{
    private static readonly byte[] IVa = new byte[] { 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x11, 0x11, 0x12, 0x13, 0x14, 0x0e, 0x16, 0x17 };


    public static string Encrypt(this string text, string salt)
    {
        try
        {
            using (Aes aes = new AesManaged())
            {
                Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(Encoding.UTF8.GetString(IVa, 0, IVa.Length), Encoding.UTF8.GetBytes(salt));
                aes.Key = deriveBytes.GetBytes(128 / 8);
                aes.IV = aes.Key;
                using (MemoryStream encryptionStream = new MemoryStream())
                {
                    using (CryptoStream encrypt = new CryptoStream(encryptionStream, aes.CreateEncryptor(), CryptoStreamMode.Write))
                    {
                        byte[] cleanText = Encoding.UTF8.GetBytes(text);
                        encrypt.Write(cleanText, 0, cleanText.Length);
                        encrypt.FlushFinalBlock();
                    }

                    byte[] encryptedData = encryptionStream.ToArray();
                    string encryptedText = Convert.ToBase64String(encryptedData);


                    return encryptedText;
                }
            }
        }
        catch
        {
            return String.Empty;
        }
    }

    public static string Decrypt(this string text, string salt)
    {
        try
        {
            using (Aes aes = new AesManaged())
            {
                Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(Encoding.UTF8.GetString(IVa, 0, IVa.Length), Encoding.UTF8.GetBytes(salt));
                aes.Key = deriveBytes.GetBytes(128 / 8);
                aes.IV = aes.Key;

                using (MemoryStream decryptionStream = new MemoryStream())
                {
                    using (CryptoStream decrypt = new CryptoStream(decryptionStream, aes.CreateDecryptor(), CryptoStreamMode.Write))
                    {
                        byte[] encryptedData = Convert.FromBase64String(text);


                        decrypt.Write(encryptedData, 0, encryptedData.Length);
                        decrypt.Flush();
                    }

                    byte[] decryptedData = decryptionStream.ToArray();
                    string decryptedText = Encoding.UTF8.GetString(decryptedData, 0, decryptedData.Length);


                    return decryptedText;
                }
            }
        }
        catch
        {
            return String.Empty;
        }
        }
    }
}

参考c#中加密和解密字符串，我找到了一个很好的解决方案:

static readonly string PasswordHash = "P@@Sw0rd";
static readonly string SaltKey = "S@LT&KEY";
static readonly string VIKey = "@1B2c3D4e5F6g7H8";

对于加密

public static string Encrypt(string plainText)
{
    byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);

    byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
    var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.Zeros };
    var encryptor = symmetricKey.CreateEncryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));

    byte[] cipherTextBytes;

    using (var memoryStream = new MemoryStream())
    {
        using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
        {
            cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
            cryptoStream.FlushFinalBlock();
            cipherTextBytes = memoryStream.ToArray();
            cryptoStream.Close();
        }
        memoryStream.Close();
    }
    return Convert.ToBase64String(cipherTextBytes);
}

对解密

public static string Decrypt(string encryptedText)
{
    byte[] cipherTextBytes = Convert.FromBase64String(encryptedText);
    byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
    var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.None };

    var decryptor = symmetricKey.CreateDecryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
    var memoryStream = new MemoryStream(cipherTextBytes);
    var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
    byte[] plainTextBytes = new byte[cipherTextBytes.Length];

    int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
    memoryStream.Close();
    cryptoStream.Close();
    return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount).TrimEnd("\0".ToCharArray());
}

字符串的对称认证加密的现代示例。

对称加密的一般最佳实践是使用关联数据的身份验证加密(AEAD)，但这不是标准.net加密库的一部分。因此，第一个示例使用AES256，然后使用HMAC256，两步加密，然后使用MAC，这需要更多的开销和更多的密钥。

第二个示例使用更简单的AES256-GCM实践，使用开源的Bouncy Castle(通过nuget)。

这两个示例都有一个main函数，该函数接受秘密消息字符串、密钥和一个可选的非秘密有效负载，并返回经过身份验证的加密字符串(可选地以非秘密数据作为前缀)。理想情况下，你会使用这些256位密钥随机生成(见NewKey())。

这两个示例都有一个助手方法，使用字符串密码生成密钥。提供这些辅助方法是为了方便与其他示例匹配，但是它们的安全性要低得多，因为密码的强度要比256位密钥弱得多。

更新: 增加了byte[]重载，由于StackOverflow的回答限制，只有Gist有4个空格缩进和api文档的完整格式。

.NET内置加密(AES)-然后mac (HMAC)[摘要]

/*
 * This work (Modern Encryption of a String C#, by James Tuley), 
 * identified by James Tuley, is free of known copyright restrictions.
 * https://gist.github.com/4336842
 * http://creativecommons.org/publicdomain/mark/1.0/ 
 */

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace Encryption
{
  public static class AESThenHMAC
  {
    private static readonly RandomNumberGenerator Random = RandomNumberGenerator.Create();

    //Preconfigured Encryption Parameters
    public static readonly int BlockBitSize = 128;
    public static readonly int KeyBitSize = 256;

    //Preconfigured Password Key Derivation Parameters
    public static readonly int SaltBitSize = 64;
    public static readonly int Iterations = 10000;
    public static readonly int MinPasswordLength = 12;

    /// <summary>
    /// Helper that generates a random key on each call.
    /// </summary>
    /// <returns></returns>
    public static byte[] NewKey()
    {
      var key = new byte[KeyBitSize / 8];
      Random.GetBytes(key);
      return key;
    }

    /// <summary>
    /// Simple Encryption (AES) then Authentication (HMAC) for a UTF8 Message.
    /// </summary>
    /// <param name="secretMessage">The secret message.</param>
    /// <param name="cryptKey">The crypt key.</param>
    /// <param name="authKey">The auth key.</param>
    /// <param name="nonSecretPayload">(Optional) Non-Secret Payload.</param>
    /// <returns>
    /// Encrypted Message
    /// </returns>
    /// <exception cref="System.ArgumentException">Secret Message Required!;secretMessage</exception>
    /// <remarks>
    /// Adds overhead of (Optional-Payload + BlockSize(16) + Message-Padded-To-Blocksize +  HMac-Tag(32)) * 1.33 Base64
    /// </remarks>
    public static string SimpleEncrypt(string secretMessage, byte[] cryptKey, byte[] authKey,
                       byte[] nonSecretPayload = null)
    {
      if (string.IsNullOrEmpty(secretMessage))
        throw new ArgumentException("Secret Message Required!", "secretMessage");

      var plainText = Encoding.UTF8.GetBytes(secretMessage);
      var cipherText = SimpleEncrypt(plainText, cryptKey, authKey, nonSecretPayload);
      return Convert.ToBase64String(cipherText);
    }

    /// <summary>
    /// Simple Authentication (HMAC) then Decryption (AES) for a secrets UTF8 Message.
    /// </summary>
    /// <param name="encryptedMessage">The encrypted message.</param>
    /// <param name="cryptKey">The crypt key.</param>
    /// <param name="authKey">The auth key.</param>
    /// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
    /// <returns>
    /// Decrypted Message
    /// </returns>
    /// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
    public static string SimpleDecrypt(string encryptedMessage, byte[] cryptKey, byte[] authKey,
                       int nonSecretPayloadLength = 0)
    {
      if (string.IsNullOrWhiteSpace(encryptedMessage))
        throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");

      var cipherText = Convert.FromBase64String(encryptedMessage);
      var plainText = SimpleDecrypt(cipherText, cryptKey, authKey, nonSecretPayloadLength);
      return plainText == null ? null : Encoding.UTF8.GetString(plainText);
    }

    /// <summary>
    /// Simple Encryption (AES) then Authentication (HMAC) of a UTF8 message
    /// using Keys derived from a Password (PBKDF2).
    /// </summary>
    /// <param name="secretMessage">The secret message.</param>
    /// <param name="password">The password.</param>
    /// <param name="nonSecretPayload">The non secret payload.</param>
    /// <returns>
    /// Encrypted Message
    /// </returns>
    /// <exception cref="System.ArgumentException">password</exception>
    /// <remarks>
    /// Significantly less secure than using random binary keys.
    /// Adds additional non secret payload for key generation parameters.
    /// </remarks>
    public static string SimpleEncryptWithPassword(string secretMessage, string password,
                             byte[] nonSecretPayload = null)
    {
      if (string.IsNullOrEmpty(secretMessage))
        throw new ArgumentException("Secret Message Required!", "secretMessage");

      var plainText = Encoding.UTF8.GetBytes(secretMessage);
      var cipherText = SimpleEncryptWithPassword(plainText, password, nonSecretPayload);
      return Convert.ToBase64String(cipherText);
    }

    /// <summary>
    /// Simple Authentication (HMAC) and then Descryption (AES) of a UTF8 Message
    /// using keys derived from a password (PBKDF2). 
    /// </summary>
    /// <param name="encryptedMessage">The encrypted message.</param>
    /// <param name="password">The password.</param>
    /// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
    /// <returns>
    /// Decrypted Message
    /// </returns>
    /// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
    /// <remarks>
    /// Significantly less secure than using random binary keys.
    /// </remarks>
    public static string SimpleDecryptWithPassword(string encryptedMessage, string password,
                             int nonSecretPayloadLength = 0)
    {
      if (string.IsNullOrWhiteSpace(encryptedMessage))
        throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");

      var cipherText = Convert.FromBase64String(encryptedMessage);
      var plainText = SimpleDecryptWithPassword(cipherText, password, nonSecretPayloadLength);
      return plainText == null ? null : Encoding.UTF8.GetString(plainText);
    }

    public static byte[] SimpleEncrypt(byte[] secretMessage, byte[] cryptKey, byte[] authKey, byte[] nonSecretPayload = null)
    {
      //User Error Checks
      if (cryptKey == null || cryptKey.Length != KeyBitSize / 8)
        throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "cryptKey");

      if (authKey == null || authKey.Length != KeyBitSize / 8)
        throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "authKey");

      if (secretMessage == null || secretMessage.Length < 1)
        throw new ArgumentException("Secret Message Required!", "secretMessage");

      //non-secret payload optional
      nonSecretPayload = nonSecretPayload ?? new byte[] { };

      byte[] cipherText;
      byte[] iv;

      using (var aes = new AesManaged
      {
        KeySize = KeyBitSize,
        BlockSize = BlockBitSize,
        Mode = CipherMode.CBC,
        Padding = PaddingMode.PKCS7
      })
      {

        //Use random IV
        aes.GenerateIV();
        iv = aes.IV;

        using (var encrypter = aes.CreateEncryptor(cryptKey, iv))
        using (var cipherStream = new MemoryStream())
        {
          using (var cryptoStream = new CryptoStream(cipherStream, encrypter, CryptoStreamMode.Write))
          using (var binaryWriter = new BinaryWriter(cryptoStream))
          {
            //Encrypt Data
            binaryWriter.Write(secretMessage);
          }

          cipherText = cipherStream.ToArray();
        }

      }

      //Assemble encrypted message and add authentication
      using (var hmac = new HMACSHA256(authKey))
      using (var encryptedStream = new MemoryStream())
      {
        using (var binaryWriter = new BinaryWriter(encryptedStream))
        {
          //Prepend non-secret payload if any
          binaryWriter.Write(nonSecretPayload);
          //Prepend IV
          binaryWriter.Write(iv);
          //Write Ciphertext
          binaryWriter.Write(cipherText);
          binaryWriter.Flush();

          //Authenticate all data
          var tag = hmac.ComputeHash(encryptedStream.ToArray());
          //Postpend tag
          binaryWriter.Write(tag);
        }
        return encryptedStream.ToArray();
      }

    }

    public static byte[] SimpleDecrypt(byte[] encryptedMessage, byte[] cryptKey, byte[] authKey, int nonSecretPayloadLength = 0)
    {

      //Basic Usage Error Checks
      if (cryptKey == null || cryptKey.Length != KeyBitSize / 8)
        throw new ArgumentException(String.Format("CryptKey needs to be {0} bit!", KeyBitSize), "cryptKey");

      if (authKey == null || authKey.Length != KeyBitSize / 8)
        throw new ArgumentException(String.Format("AuthKey needs to be {0} bit!", KeyBitSize), "authKey");

      if (encryptedMessage == null || encryptedMessage.Length == 0)
        throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");

      using (var hmac = new HMACSHA256(authKey))
      {
        var sentTag = new byte[hmac.HashSize / 8];
        //Calculate Tag
        var calcTag = hmac.ComputeHash(encryptedMessage, 0, encryptedMessage.Length - sentTag.Length);
        var ivLength = (BlockBitSize / 8);

        //if message length is to small just return null
        if (encryptedMessage.Length < sentTag.Length + nonSecretPayloadLength + ivLength)
          return null;

        //Grab Sent Tag
        Array.Copy(encryptedMessage, encryptedMessage.Length - sentTag.Length, sentTag, 0, sentTag.Length);

        //Compare Tag with constant time comparison
        var compare = 0;
        for (var i = 0; i < sentTag.Length; i++)
          compare |= sentTag[i] ^ calcTag[i]; 

        //if message doesn't authenticate return null
        if (compare != 0)
          return null;

        using (var aes = new AesManaged
        {
          KeySize = KeyBitSize,
          BlockSize = BlockBitSize,
          Mode = CipherMode.CBC,
          Padding = PaddingMode.PKCS7
        })
        {

          //Grab IV from message
          var iv = new byte[ivLength];
          Array.Copy(encryptedMessage, nonSecretPayloadLength, iv, 0, iv.Length);

          using (var decrypter = aes.CreateDecryptor(cryptKey, iv))
          using (var plainTextStream = new MemoryStream())
          {
            using (var decrypterStream = new CryptoStream(plainTextStream, decrypter, CryptoStreamMode.Write))
            using (var binaryWriter = new BinaryWriter(decrypterStream))
            {
              //Decrypt Cipher Text from Message
              binaryWriter.Write(
                encryptedMessage,
                nonSecretPayloadLength + iv.Length,
                encryptedMessage.Length - nonSecretPayloadLength - iv.Length - sentTag.Length
              );
            }
            //Return Plain Text
            return plainTextStream.ToArray();
          }
        }
      }
    }

    public static byte[] SimpleEncryptWithPassword(byte[] secretMessage, string password, byte[] nonSecretPayload = null)
    {
      nonSecretPayload = nonSecretPayload ?? new byte[] {};

      //User Error Checks
      if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
        throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");

      if (secretMessage == null || secretMessage.Length ==0)
        throw new ArgumentException("Secret Message Required!", "secretMessage");

      var payload = new byte[((SaltBitSize / 8) * 2) + nonSecretPayload.Length];

      Array.Copy(nonSecretPayload, payload, nonSecretPayload.Length);
      int payloadIndex = nonSecretPayload.Length;

      byte[] cryptKey;
      byte[] authKey;
      //Use Random Salt to prevent pre-generated weak password attacks.
      using (var generator = new Rfc2898DeriveBytes(password, SaltBitSize / 8, Iterations))
      {
        var salt = generator.Salt;

        //Generate Keys
        cryptKey = generator.GetBytes(KeyBitSize / 8);

        //Create Non Secret Payload
        Array.Copy(salt, 0, payload, payloadIndex, salt.Length);
        payloadIndex += salt.Length;
      }

      //Deriving separate key, might be less efficient than using HKDF, 
      //but now compatible with RNEncryptor which had a very similar wireformat and requires less code than HKDF.
      using (var generator = new Rfc2898DeriveBytes(password, SaltBitSize / 8, Iterations))
      {
        var salt = generator.Salt;

        //Generate Keys
        authKey = generator.GetBytes(KeyBitSize / 8);

        //Create Rest of Non Secret Payload
        Array.Copy(salt, 0, payload, payloadIndex, salt.Length);
      }

      return SimpleEncrypt(secretMessage, cryptKey, authKey, payload);
    }

    public static byte[] SimpleDecryptWithPassword(byte[] encryptedMessage, string password, int nonSecretPayloadLength = 0)
    {
      //User Error Checks
      if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
        throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");

      if (encryptedMessage == null || encryptedMessage.Length == 0)
        throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");

      var cryptSalt = new byte[SaltBitSize / 8];
      var authSalt = new byte[SaltBitSize / 8];

      //Grab Salt from Non-Secret Payload
      Array.Copy(encryptedMessage, nonSecretPayloadLength, cryptSalt, 0, cryptSalt.Length);
      Array.Copy(encryptedMessage, nonSecretPayloadLength + cryptSalt.Length, authSalt, 0, authSalt.Length);

      byte[] cryptKey;
      byte[] authKey;

      //Generate crypt key
      using (var generator = new Rfc2898DeriveBytes(password, cryptSalt, Iterations))
      {
        cryptKey = generator.GetBytes(KeyBitSize / 8);
      }
      //Generate auth key
      using (var generator = new Rfc2898DeriveBytes(password, authSalt, Iterations))
      {
        authKey = generator.GetBytes(KeyBitSize / 8);
      }

      return SimpleDecrypt(encryptedMessage, cryptKey, authKey, cryptSalt.Length + authSalt.Length + nonSecretPayloadLength);
    }
  }
}

弹力城堡AES-GCM[摘要]

/*
 * This work (Modern Encryption of a String C#, by James Tuley), 
 * identified by James Tuley, is free of known copyright restrictions.
 * https://gist.github.com/4336842
 * http://creativecommons.org/publicdomain/mark/1.0/ 
 */

using System;
using System.IO;
using System.Text;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Modes;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
namespace Encryption
{

  public static class AESGCM
  {
    private static readonly SecureRandom Random = new SecureRandom();

    //Preconfigured Encryption Parameters
    public static readonly int NonceBitSize = 128;
    public static readonly int MacBitSize = 128;
    public static readonly int KeyBitSize = 256;

    //Preconfigured Password Key Derivation Parameters
    public static readonly int SaltBitSize = 128;
    public static readonly int Iterations = 10000;
    public static readonly int MinPasswordLength = 12;


    /// <summary>
    /// Helper that generates a random new key on each call.
    /// </summary>
    /// <returns></returns>
    public static byte[] NewKey()
    {
      var key = new byte[KeyBitSize / 8];
      Random.NextBytes(key);
      return key;
    }

    /// <summary>
    /// Simple Encryption And Authentication (AES-GCM) of a UTF8 string.
    /// </summary>
    /// <param name="secretMessage">The secret message.</param>
    /// <param name="key">The key.</param>
    /// <param name="nonSecretPayload">Optional non-secret payload.</param>
    /// <returns>
    /// Encrypted Message
    /// </returns>
    /// <exception cref="System.ArgumentException">Secret Message Required!;secretMessage</exception>
    /// <remarks>
    /// Adds overhead of (Optional-Payload + BlockSize(16) + Message +  HMac-Tag(16)) * 1.33 Base64
    /// </remarks>
    public static string SimpleEncrypt(string secretMessage, byte[] key, byte[] nonSecretPayload = null)
    {
      if (string.IsNullOrEmpty(secretMessage))
        throw new ArgumentException("Secret Message Required!", "secretMessage");

      var plainText = Encoding.UTF8.GetBytes(secretMessage);
      var cipherText = SimpleEncrypt(plainText, key, nonSecretPayload);
      return Convert.ToBase64String(cipherText);
    }


    /// <summary>
    /// Simple Decryption & Authentication (AES-GCM) of a UTF8 Message
    /// </summary>
    /// <param name="encryptedMessage">The encrypted message.</param>
    /// <param name="key">The key.</param>
    /// <param name="nonSecretPayloadLength">Length of the optional non-secret payload.</param>
    /// <returns>Decrypted Message</returns>
    public static string SimpleDecrypt(string encryptedMessage, byte[] key, int nonSecretPayloadLength = 0)
    {
      if (string.IsNullOrEmpty(encryptedMessage))
        throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");

      var cipherText = Convert.FromBase64String(encryptedMessage);
      var plainText = SimpleDecrypt(cipherText, key, nonSecretPayloadLength);
      return plainText == null ? null : Encoding.UTF8.GetString(plainText);
    }

    /// <summary>
    /// Simple Encryption And Authentication (AES-GCM) of a UTF8 String
    /// using key derived from a password (PBKDF2).
    /// </summary>
    /// <param name="secretMessage">The secret message.</param>
    /// <param name="password">The password.</param>
    /// <param name="nonSecretPayload">The non secret payload.</param>
    /// <returns>
    /// Encrypted Message
    /// </returns>
    /// <remarks>
    /// Significantly less secure than using random binary keys.
    /// Adds additional non secret payload for key generation parameters.
    /// </remarks>
    public static string SimpleEncryptWithPassword(string secretMessage, string password,
                             byte[] nonSecretPayload = null)
    {
      if (string.IsNullOrEmpty(secretMessage))
        throw new ArgumentException("Secret Message Required!", "secretMessage");

      var plainText = Encoding.UTF8.GetBytes(secretMessage);
      var cipherText = SimpleEncryptWithPassword(plainText, password, nonSecretPayload);
      return Convert.ToBase64String(cipherText);
    }


    /// <summary>
    /// Simple Decryption and Authentication (AES-GCM) of a UTF8 message
    /// using a key derived from a password (PBKDF2)
    /// </summary>
    /// <param name="encryptedMessage">The encrypted message.</param>
    /// <param name="password">The password.</param>
    /// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
    /// <returns>
    /// Decrypted Message
    /// </returns>
    /// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
    /// <remarks>
    /// Significantly less secure than using random binary keys.
    /// </remarks>
    public static string SimpleDecryptWithPassword(string encryptedMessage, string password,
                             int nonSecretPayloadLength = 0)
    {
      if (string.IsNullOrWhiteSpace(encryptedMessage))
        throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");

      var cipherText = Convert.FromBase64String(encryptedMessage);
      var plainText = SimpleDecryptWithPassword(cipherText, password, nonSecretPayloadLength);
      return plainText == null ? null : Encoding.UTF8.GetString(plainText);
    }

    public static byte[] SimpleEncrypt(byte[] secretMessage, byte[] key, byte[] nonSecretPayload = null)
    {
      //User Error Checks
      if (key == null || key.Length != KeyBitSize / 8)
        throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "key");

      if (secretMessage == null || secretMessage.Length == 0)
        throw new ArgumentException("Secret Message Required!", "secretMessage");

      //Non-secret Payload Optional
      nonSecretPayload = nonSecretPayload ?? new byte[] { };

      //Using random nonce large enough not to repeat
      var nonce = new byte[NonceBitSize / 8];
      Random.NextBytes(nonce, 0, nonce.Length);

      var cipher = new GcmBlockCipher(new AesFastEngine());
      var parameters = new AeadParameters(new KeyParameter(key), MacBitSize, nonce, nonSecretPayload);
      cipher.Init(true, parameters);

      //Generate Cipher Text With Auth Tag
      var cipherText = new byte[cipher.GetOutputSize(secretMessage.Length)];
      var len = cipher.ProcessBytes(secretMessage, 0, secretMessage.Length, cipherText, 0);
      cipher.DoFinal(cipherText, len);

      //Assemble Message
      using (var combinedStream = new MemoryStream())
      {
        using (var binaryWriter = new BinaryWriter(combinedStream))
        {
          //Prepend Authenticated Payload
          binaryWriter.Write(nonSecretPayload);
          //Prepend Nonce
          binaryWriter.Write(nonce);
          //Write Cipher Text
          binaryWriter.Write(cipherText);
        }
        return combinedStream.ToArray();
      }
    }

    public static byte[] SimpleDecrypt(byte[] encryptedMessage, byte[] key, int nonSecretPayloadLength = 0)
    {
      //User Error Checks
      if (key == null || key.Length != KeyBitSize / 8)
        throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "key");

      if (encryptedMessage == null || encryptedMessage.Length == 0)
        throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");

      using (var cipherStream = new MemoryStream(encryptedMessage))
      using (var cipherReader = new BinaryReader(cipherStream))
      {
        //Grab Payload
        var nonSecretPayload = cipherReader.ReadBytes(nonSecretPayloadLength);

        //Grab Nonce
        var nonce = cipherReader.ReadBytes(NonceBitSize / 8);

        var cipher = new GcmBlockCipher(new AesFastEngine());
        var parameters = new AeadParameters(new KeyParameter(key), MacBitSize, nonce, nonSecretPayload);
        cipher.Init(false, parameters);

        //Decrypt Cipher Text
        var cipherText = cipherReader.ReadBytes(encryptedMessage.Length - nonSecretPayloadLength - nonce.Length);
        var plainText = new byte[cipher.GetOutputSize(cipherText.Length)];  

        try
        {
          var len = cipher.ProcessBytes(cipherText, 0, cipherText.Length, plainText, 0);
          cipher.DoFinal(plainText, len);

        }
        catch (InvalidCipherTextException)
        {
          //Return null if it doesn't authenticate
          return null;
        }

        return plainText;
      }

    }

    public static byte[] SimpleEncryptWithPassword(byte[] secretMessage, string password, byte[] nonSecretPayload = null)
    {
      nonSecretPayload = nonSecretPayload ?? new byte[] {};

      //User Error Checks
      if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
        throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");

      if (secretMessage == null || secretMessage.Length == 0)
        throw new ArgumentException("Secret Message Required!", "secretMessage");

      var generator = new Pkcs5S2ParametersGenerator();

      //Use Random Salt to minimize pre-generated weak password attacks.
      var salt = new byte[SaltBitSize / 8];
      Random.NextBytes(salt);

      generator.Init(
        PbeParametersGenerator.Pkcs5PasswordToBytes(password.ToCharArray()),
        salt,
        Iterations);

      //Generate Key
      var key = (KeyParameter)generator.GenerateDerivedMacParameters(KeyBitSize);

      //Create Full Non Secret Payload
      var payload = new byte[salt.Length + nonSecretPayload.Length];
      Array.Copy(nonSecretPayload, payload, nonSecretPayload.Length);
      Array.Copy(salt,0, payload,nonSecretPayload.Length, salt.Length);

      return SimpleEncrypt(secretMessage, key.GetKey(), payload);
    }

    public static byte[] SimpleDecryptWithPassword(byte[] encryptedMessage, string password, int nonSecretPayloadLength = 0)
    {
      //User Error Checks
      if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
        throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");

      if (encryptedMessage == null || encryptedMessage.Length == 0)
        throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");

      var generator = new Pkcs5S2ParametersGenerator();

      //Grab Salt from Payload
      var salt = new byte[SaltBitSize / 8];
      Array.Copy(encryptedMessage, nonSecretPayloadLength, salt, 0, salt.Length);

      generator.Init(
        PbeParametersGenerator.Pkcs5PasswordToBytes(password.ToCharArray()),
        salt,
        Iterations);

      //Generate Key
      var key = (KeyParameter)generator.GenerateDerivedMacParameters(KeyBitSize);

      return SimpleDecrypt(encryptedMessage, key.GetKey(), salt.Length + nonSecretPayloadLength);
    }
  }
}

支持mattmanser的回答。下面是一个使用MachineKey类加密/解密URL安全值的示例。

Something to bear in mind, as mentioned before, this will use Machine config settings (https://msdn.microsoft.com/en-us/library/ff649308.aspx). You can set encryption and decryption key/algorithm manually (you might need this specially if your site is running on multiple servers) in web.config file. You can generate keys from IIS (see here: https://blogs.msdn.microsoft.com/vijaysk/2009/05/13/iis-7-tip-10-you-can-generate-machine-keys-from-the-iis-manager/) or can use an online machine key generator like: http://www.developerfusion.com/tools/generatemachinekey/

    private static readonly UTF8Encoding Encoder = new UTF8Encoding();

    public static string Encrypt(string unencrypted)
    {
        if (string.IsNullOrEmpty(unencrypted)) 
            return string.Empty;

        try
        {
            var encryptedBytes = MachineKey.Protect(Encoder.GetBytes(unencrypted));

            if (encryptedBytes != null && encryptedBytes.Length > 0)
                return HttpServerUtility.UrlTokenEncode(encryptedBytes);    
        }
        catch (Exception)
        {
            return string.Empty;
        }

        return string.Empty;
    }

    public static string Decrypt(string encrypted)
    {
        if (string.IsNullOrEmpty(encrypted)) 
            return string.Empty;

        try
        {
            var bytes = HttpServerUtility.UrlTokenDecode(encrypted);
            if (bytes != null && bytes.Length > 0)
            {
                var decryptedBytes = MachineKey.Unprotect(bytes);
                if(decryptedBytes != null && decryptedBytes.Length > 0)
                    return Encoder.GetString(decryptedBytes);
            }

        }
        catch (Exception)
        {
            return string.Empty;
        }

        return string.Empty;
    }

这是一个简单的Snippet，最初由ASP Snippet编写

using System.Text;
using System.Security.Cryptography;
using System.IO;


 private string Encrypt(string clearText)
    {
        string EncryptionKey = "yourkey";
        byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
        using (Aes encryptor = Aes.Create())
        {
            Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
            encryptor.Key = pdb.GetBytes(32);
            encryptor.IV = pdb.GetBytes(16);
            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
                {
                    cs.Write(clearBytes, 0, clearBytes.Length);
                    cs.Close();
                }
                clearText = Convert.ToBase64String(ms.ToArray());
            }
        }
        return clearText;
    }

 private string Decrypt(string cipherText)
    {
        string EncryptionKey = "yourkey";
        cipherText = cipherText.Replace(" ", "+");
        byte[] cipherBytes = Convert.FromBase64String(cipherText);
        using (Aes encryptor = Aes.Create())
        {
            Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
            encryptor.Key = pdb.GetBytes(32);
            encryptor.IV = pdb.GetBytes(16);
            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
                {
                    cs.Write(cipherBytes, 0, cipherBytes.Length);
                    cs.Close();
                }
                cipherText = Encoding.Unicode.GetString(ms.ToArray());
            }
        }
        return cipherText;
    }