using System;

using System.Security.Cryptography;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        var ssn = "656786543";

        var dob = "01-01-2002";

​

        string plainData = $"{ssn}{dob}";  

        Console.WriteLine("Raw data: {0}", plainData);  

        string hashedData = ComputeSha256Hash(plainData);  

        Console.WriteLine("Hash {0}", hashedData);  

        Console.WriteLine("Second Time {0}", ComputeSha256Hash($"{ssn}{dob}"));  

        Console.WriteLine("Third Time {0}", ComputeSha256Hash($"{ssn}{dob}"));  

        Console.WriteLine("Fourth Time {0}", ComputeSha256Hash($"{ssn}{dob}"));

        Console.WriteLine("Fifth Time {0}", ComputeSha256Hash($"{ssn}{dob}"));  

    }

    //https://www.c-sharpcorner.com/article/compute-sha256-hash-in-c-sharp/

        static string ComputeSha256Hash(string rawData)  

        {  

            // Create a SHA256   

            using (SHA256 sha256Hash = SHA256.Create())  

            {  

                // ComputeHash - returns byte array  

                byte[] bytes = sha256Hash.ComputeHash(Encoding.UTF8.GetBytes(rawData));  

                // Convert byte array to a string   

                StringBuilder builder = new StringBuilder();  

                for (int i = 0; i < bytes.Length; i++)  

                {  

                    builder.Append(bytes[i].ToString("x2"));  

                }  

                return builder.ToString();  

            }  

        }  

}