Encrypt And Decrypt Using Digital Signatures

Now in continutaion to my earlier artcile the mirroe link of the article here I am going to describe how we can use the digital signatures for the purpose of Encryption and Decryption.

The Following code will show how we can encrypt the plain text.

Encryption

#region Encryption

public string GetEncryptedText(string PlainStringToEncrypt)

{

try

{

string PlainString = PlainStringToEncrypt.Trim();

byte[] cipherbytes = ASCIIEncoding.ASCII.GetBytes(PlainString);

RSACryptoServiceProvider rsa = (RSACryptoServiceProvider)x509_2.PublicKey.Key;

byte[] cipher = rsa.Encrypt(cipherbytes, false);

return Convert.ToBase64String(cipher);

}

catch (Exception e)

{

throw e;

}

}

#endregion

Now once we have encrypted text we need to decrypt it. the following section of code will demonstrate how to decrypt that encrypted text.

Decryption

#region Decryption

public string GetDecryptedText(string EncryptedStringToDecrypt)

{

try

{



try

{

byte[] cipherbytes = Convert.FromBase64String(EncryptedStringToDecrypt);

if (x509_2.HasPrivateKey)

{

RSACryptoServiceProvider rsa = (RSACryptoServiceProvider)x509_2.PrivateKey;

byte[] plainbytes = rsa.Decrypt(cipherbytes, false);

System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();

return enc.GetString(plainbytes);

}

else

{

throw new Exception("Certificate used for has no private key.");

}

}

catch (Exception e)

{

return e.Message;

}

}

catch

{

return EncryptedStringToDecrypt;

}

}

#endregion

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Thanks and Regards

Meetu Choudhary