// (c) 2006 Richard Grimes
// www.grimes.demon.co.uk

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

class App
{
   static void Main()
   {
      RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
      string clearText = "the quick brown fox...";
      byte[] data = Encoding.ASCII.GetBytes(clearText);
      RSAPKCS1SignatureFormatter formatter = new RSAPKCS1SignatureFormatter(rsa);
      formatter.SetHashAlgorithm("SHA1");
      SHA1 sha = SHA1.Create();
      byte[] hash = sha.ComputeHash(data);
      byte[] sign = formatter.CreateSignature(hash);
      Console.WriteLine(BitConverter.ToString(sign));
      RSAPKCS1SignatureDeformatter deformatter = new RSAPKCS1SignatureDeformatter(rsa);
      deformatter.SetHashAlgorithm("SHA1");
      bool bVerify = deformatter.VerifySignature(hash, sign);
      Console.WriteLine("signature is verified: {0}", bVerify);
   }
}