How to use public and private key encryption technique in C#

Question

I want to encrypt data using public/private key technique. I mean, encrypt with the public key of receiver and the receiver can decrypt with their own private key.

How can I do that? Do you have any suggestion or sample code ?

Answer 1

Code example:

private static string _privateKey; private static string _publicKey; private static UnicodeEncoding _encoder = new UnicodeEncoding();  private static void RSA() {   var rsa = new RSACryptoServiceProvider();   _privateKey = rsa.ToXmlString(true);   _publicKey = rsa.ToXmlString(false);    var text = "Test1";   Console.WriteLine("RSA // Text to encrypt: " + text);   var enc = Encrypt(text);   Console.WriteLine("RSA // Encrypted Text: " + enc);   var dec = Decrypt(enc);   Console.WriteLine("RSA // Decrypted Text: " + dec); }  public static string Decrypt(string data) {   var rsa = new RSACryptoServiceProvider();   var dataArray = data.Split(new char[] { ',' });   byte[] dataByte = new byte[dataArray.Length];   for (int i = 0; i < dataArray.Length; i++)   {     dataByte[i] = Convert.ToByte(dataArray[i]);   }    rsa.FromXmlString(_privateKey);   var decryptedByte = rsa.Decrypt(dataByte, false);   return _encoder.GetString(decryptedByte); }  public static string Encrypt(string data) {   var rsa = new RSACryptoServiceProvider();   rsa.FromXmlString(_publicKey);   var dataToEncrypt = _encoder.GetBytes(data);   var encryptedByteArray = rsa.Encrypt(dataToEncrypt, false).ToArray();   var length = encryptedByteArray.Count();   var item = 0;   var sb = new StringBuilder();   foreach (var x in encryptedByteArray)   {     item++;     sb.Append(x);      if (item < length)       sb.Append(",");   }    return sb.ToString(); }