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

namespace ConsoleApp1
{
    class Program
    {

        private static RSAParameters PublicKey { get; set; }
        private static RSAParameters PrivateKey { get; set; }

        static void Main(string[] args)
        {
            GenerateKey();

            var message = "this is a test";
            byte[] encrypted = Encrypt(Encoding.UTF8.GetBytes(message));
            byte[] decrypted = Decrypt(encrypted);

            Console.WriteLine("Original: " + message + "\n");
            Console.WriteLine("Encrypted: " + BitConverter.ToString(encrypted) + "\n");
            Console.WriteLine("Decrypted: " + Encoding.UTF8.GetString(decrypted));

            Console.ReadLine();
        }


        public static void GenerateKey()
        {
            using (var rsa = new RSACryptoServiceProvider(2048))
            {
                rsa.PersistKeyInCsp = false;
                PublicKey = rsa.ExportParameters(false);
                PrivateKey = rsa.ExportParameters(true);
            }
        }

        public static byte[] Encrypt(byte[] input)
        {
            byte[] encrypted;
            using (var rsa = new RSACryptoServiceProvider(2048))
            {
                rsa.PersistKeyInCsp = false;
                rsa.ImportParameters(PublicKey);
                encrypted = rsa.Encrypt(input, true);
            }

            return encrypted;
        }

        public static byte[] Decrypt(byte[] input)
        {
            byte[] decrypted;
            using (var rsa = new RSACryptoServiceProvider(2048))
            {
                rsa.PersistKeyInCsp = false;
                rsa.ImportParameters(PrivateKey);
                decrypted = rsa.Decrypt(input, true);
            }
            return decrypted;
        }
    }
}