【加密算法】Base64

/// <summary>
/// Base64加密解密
/// 密文用在url，注意+的转义
/// </summary>
public class Base64Helper
{
    /// <summary>
    /// Base64加密 可逆
    /// </summary>
    /// <param name="plaintext">待加密文本</param>
    /// <returns></returns>
    public static string Encrypt(string plaintext)
    {
        if (String.IsNullOrEmpty(plaintext))
        {
            throw new ArgumentNullException("明文不能为空");
        }

        byte[] data = Encoding.UTF8.GetBytes(plaintext);
        return Convert.ToBase64String(data);
    }

    /// <summary>
    /// Base64解密
    /// </summary>
    /// <param name="ciphertext">密文</param>
    /// <returns></returns>
    public static string Decrypt(string ciphertext)
    {
        if (String.IsNullOrEmpty(ciphertext))
        {
            throw new ArgumentNullException("密文不能为空");
        }
        byte[] data = Convert.FromBase64String(ciphertext);
        return Encoding.UTF8.GetString(data);
    }
}