关于私钥加密,公钥解密的算法安全.网上介绍的大素数那个方法可靠么?求算法达人

[待解决问题]

正在做不对称加密,知道公钥加密,私钥解密和私钥加密,公钥解密原理上应该是对称的.并且也的确都会用到.但微软似乎没有提供私钥加密,公钥解密的东东.

于是查了一下,找到很多介绍大素数加密的.

以下代码是直接粘贴别人的,我算法方面不是太好,希望达人给看看,这样的算法安全么?即使原封不动的使用,也就是说别人知道我的算法,安全上也没问题么?我个人也在很努力的想懂这个算法.

功能：用指定的私钥(n,d)加密指定字符串source

string EncryptString(string source, BigInteger d, BigInteger n)

private string EncryptString(string source, BigInteger d, BigInteger n) 
                ...{ 
                        int len = source.Length; 
                        int len1 = 0; 
                        int blockLen = 0; 
                        if ((len % 128) == 0) 
                                len1 = len / 128; 
                        else 
                                len1 = len / 128 + 1; 
                        string block = ""; 
                        string temp = ""; 
                        for (int i = 0; i < len1; i++) 
                        ...{ 
                                if (len >= 128) 
                                        blockLen = 128; 
                                else 
                                        blockLen = len; 
                                block = source.Substring(i * 128, blockLen); 
                                byte[] oText = System.Text.Encoding.Default.GetBytes(block); 
                                BigInteger biText = new BigInteger(oText); 
                                BigInteger biEnText = biText.modPow(d, n); 
                                string temp1 = biEnText.ToHexString(); 
                                temp += temp1; 
                                len -= blockLen; 
                        } 
                        return temp; 
                }

功能：用指定的公钥(n,e)解密指定字符串source

string DecryptString(string source, BigInteger e, BigInteger n)

private string DecryptString(string source, BigInteger e, BigInteger n) 
                ...{ 
                        int len = source.Length; 
                        int len1 = 0; 
                        int blockLen = 0; 
                        if ((len % 256) == 0) 
                                len1 = len / 256; 
                        else 
                                len1 = len / 256 + 1; 
                        string block = ""; 
                        string temp = ""; 
                        for (int i = 0; i < len1; i++) 
                        ...{ 
                                if (len >= 256) 
                                        blockLen = 256; 
                                else 
                                        blockLen = len; 
                                block = source.Substring(i * 256, blockLen); 
                                BigInteger biText = new BigInteger(block, 16); 
                                BigInteger biEnText = biText.modPow(e, n); 
                                string temp1 = System.Text.Encoding.Default.GetString(biEnText.getBytes()); 
                                temp += temp1; 
                                len -= blockLen; 
                        } 
                        return temp; 
                }

加密过程和解密过程代码如下所示：

加密过程,其中d、n是RSACryptoServiceProvider生成的D、Modulus

string EncryptProcess(string source, string d, string n)

                private string EncryptProcess(string source, string d, string n) 
                ...{ 
                        byte[] N = Convert.FromBase64String(n); 
                        byte[] D = Convert.FromBase64String(d); 
                        BigInteger biN = new BigInteger(N); 
                        BigInteger biD = new BigInteger(D); 
                        return EncryptString(source, biD, biN); 
                }

解密过程,其中e、n是RSACryptoServiceProvider生成的Exponent、Modulus

DecryptProcess(string source, string e, string n)

private string DecryptProcess(string source, string e, string n) 
                ...{ 
                        byte[] N = Convert.FromBase64String(n); 
                        byte[] E = Convert.FromBase64String(e); 
                        BigInteger biN = new BigInteger(N); 
                        BigInteger biE = new BigInteger(E); 
                        return DecryptString(source, biE, biN); 
                }