在unity中能够使用c#自带的对称算法对数据进行加密，以下两种加密算法：

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

using UnityEngine;

public class StringEncryption{

#region  方法一 C#中对字符串加密解密（对称算法）  
private static byte\[\] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };  
/// <summary>  
/// DES加密字符串  
/// </summary>  
/// <param name="encryptString">待加密的字符串</param>  
/// <param name="encryptKey">加密密钥,要求为8位</param>  
/// <returns>加密成功返回加密后的字符串，失败返回源串</returns>  
public static string EncryptDES(string encryptString, string encryptKey)  
{  
    try  
    {  
        byte\[\] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));  
        byte\[\] rgbIV = Keys;  
        byte\[\] inputByteArray = Encoding.UTF8.GetBytes(encryptString);  
        DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();  
        MemoryStream mStream = new MemoryStream();  
        CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);  
        cStream.Write(inputByteArray, 0, inputByteArray.Length);  
        cStream.FlushFinalBlock();  
        cStream.Close();  
        return Convert.ToBase64String(mStream.ToArray());  
    }  
    catch  
    {  
        return encryptString;  
    }  
}

/// <summary>  
/// DES解密字符串  
/// </summary>  
/// <param name="decryptString">待解密的字符串</param>  
/// <param name="decryptKey">解密密钥,要求为8位,和加密密钥同样</param>  
/// <returns>解密成功返回解密后的字符串，失败返源串</returns>  
public static string DecryptDES(string decryptString, string decryptKey)  
{  
    try  
    {  
        byte\[\] rgbKey = Encoding.UTF8.GetBytes(decryptKey);  
        byte\[\] rgbIV = Keys;  
        byte\[\] inputByteArray = Convert.FromBase64String(decryptString);  
        DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();  
        MemoryStream mStream = new MemoryStream();  
        CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);  
        cStream.Write(inputByteArray, 0, inputByteArray.Length);  
        cStream.FlushFinalBlock();  
        cStream.Close();  
        return Encoding.UTF8.GetString(mStream.ToArray());  
    }  
    catch  
    {  
        Debug.Log("catch");  
        return decryptString;  
    }  
}  
#endregion

#region MD5不可逆加密  
//32位加密  
public string GetMD5\_32(string s, string \_input\_charset)  
{  
    MD5 md5 = new MD5CryptoServiceProvider();  
    byte\[\] t = md5.ComputeHash(Encoding.GetEncoding(\_input\_charset).GetBytes(s));  
    StringBuilder sb = new StringBuilder(32);  
    for (int i = 0; i < t.Length; i++)  
    {  
        sb.Append(t\[i\].ToString("x").PadLeft(2, '0'));  
    }  
    return sb.ToString();  
} 

//16位加密  
public static string GetMd5\_16(string ConvertString)  
{  
    MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();  
    string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);  
    t2 = t2.Replace("-", "");  
    return t2;  
}  
#endregion  

}