//引入命名空间
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

class Alice
{
    public static void Main(string[] args)
    {
        Bob bob = new Bob();
        using (ECDsaCng dsa = new ECDsaCng())
        {
            dsa.HashAlgorithm = CngAlgorithm.Sha256;
             bob.key = dsa.Key.Export(CngKeyBlobFormat.EccPublicBlob);

             byte[] data = new byte[] { 21, 5, 8, 12, 207 };

             byte[] signature = dsa.SignData(data);

             bob.Receive(data, signature);
            }
    }
}
public class Bob 
{
    public byte[] key;

    public void Receive(byte[] data, byte[] signature)
    {
        using (ECDsaCng ecsdKey = new ECDsaCng(CngKey.Import(key, CngKeyBlobFormat.EccPublicBlob)))
        {
            if (ecsdKey.VerifyData(data, signature))
                Console.WriteLine("Data is good");
            else
                Console.WriteLine("Data is bad");
        }
    }
}