KeyedHashAlgorithm: Key

   
 
using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;
class MainClass {
    public static void Main(string[] args) {
        byte[] key = Encoding.Unicode.GetBytes(args[2]);

        using (KeyedHashAlgorithm hashAlg = KeyedHashAlgorithm.Create(args[1])) {
            hashAlg.Key = key;

            using (Stream file = new FileStream(args[0], FileMode.Open, FileAccess.Read)) {
                byte[] hash = hashAlg.ComputeHash(file);

                Console.WriteLine(BitConverter.ToString(hash));
            }
        }
    }
}