C#中DES加密在PHP中解密

我写了一个Ｃ#应用程序，需要向ＰＨＰ页面提交一段加密的数据。Ｃ#用的ＤＥＳ加密算法。算法如下：C# code:
public class Crypt
{
/// <summary>
/// 创建Key
/// </summary>
/// <returns></returns>
public string GenerateKey()
{
DESCryptoServiceProvider desCrypto = (DESCryptoServiceProvider)DESCryptoServiceProvider.Create();
return ASCIIEncoding.ASCII.GetString(desCrypto.Key);
}

/// <summary>
/// 加密字符串
/// </summary>
/// <param name="sInputString"></param>
/// <param name="sKey"></param>
/// <returns></returns>
public string EncryptString(string sInputString, string sKey)
{
byte [] data = Encoding.UTF8.GetBytes(sInputString);
DESCryptoServiceProvider DES = new DESCryptoServiceProvider();
DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
ICryptoTransform desencrypt = DES.CreateEncryptor();
byte [] result = desencrypt.TransformFinalBlock(data, 0, data.Length);
return BitConverter.ToString(result);
}


/// <summary>
/// 解密字符串
/// </