using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.BouncyCastle.Math;

namespace SeansECDSAtest
{
    class Program
    {
        static void Main(string[] args)
        {
            BigInteger R = new BigInteger(StringToByteArray("00d47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1"));
            BigInteger S = new BigInteger(StringToByteArray("0044e1ff2dfd8102cf7a47c21d5c9fd5701610d04953c6836596b4fe9dd2f53e3e"));
            BigInteger Z = new BigInteger(StringToByteArray("00c0e2d0a89a348de88fda08211c70d1d7e52ccef2eb9459911bf977d587784c6e"));
            BigInteger X = new BigInteger(StringToByteArray("00c477f9f65c22cce20657faa5b2d1d8122336f851a508a1ed04e479c34985bf96"));
            BigInteger K = new BigInteger(StringToByteArray("007a1a7e52797fc8caaa435d2a4dace39158504bf204fbe19f14dbb427faee50ae"));
            BigInteger N = new BigInteger(StringToByteArray("00FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141"));

            //proving R = (((S * K) - Z) / X) % N
            var verifyR = S.Multiply(K).Subtract(Z).Multiply(X.ModInverse(N)).Mod(N);
            Console.WriteLine("R = " + string.Concat(verifyR.ToByteArrayUnsigned().Select(b => b.ToString("X2"))));

            //proving S = ((Z + (X * R)) / K) % N
            var verifyS = Z.Add(X.Multiply(R)).Multiply(K.ModInverse(N)).Mod(N);
            Console.WriteLine("S = " + string.Concat(verifyS.ToByteArrayUnsigned().Select(b => b.ToString("X2"))));

            //proving Z = ((S * K) - (X * R)) % N
            var verifyZ = S.Multiply(K).Subtract(X.Multiply(R)).Mod(N);
            Console.WriteLine("Z = " + string.Concat(verifyZ.ToByteArrayUnsigned().Select(b => b.ToString("X2"))));

            //proving X = (((S * K) - Z) / R) % N
            var verifyX = S.Multiply(K).Subtract(Z).Multiply(R.ModInverse(N)).Mod(N);
            Console.WriteLine("X = " + string.Concat(verifyX.ToByteArrayUnsigned().Select(b => b.ToString("X2"))));

            //proving K = ((Z + (X * R)) / S) % N
            var verifyK = Z.Add(X.Multiply(R)).Multiply(S.ModInverse(N)).Mod(N);
            Console.WriteLine("K = " + string.Concat(verifyK.ToByteArrayUnsigned().Select(b => b.ToString("X2"))));

            Console.ReadLine();
        }

        public static byte[] StringToByteArray(string hex)
        {
            return Enumerable.Range(0, hex.Length)
                             .Where(x => x % 2 == 0)
                             .Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
                             .ToArray();
        }
    }
}
by

C Sharp Online Compiler

Write, Run & Share C# code online using OneCompiler's C# online compiler for free. It's one of the robust, feature-rich online compilers for C# language, running on the latest version 8.0. Getting started with the OneCompiler's C# compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C# and start coding.

Read inputs from stdin

OneCompiler's C# online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

using System;
 
namespace Sample
{
  class Test
    {
      public static void Main(string[] args)
       {
         string name;
         name = Console.ReadLine();
         Console.WriteLine("Hello {0} ", name);
	}
     }
}

About C Sharp

C# is a general purpose object-oriented programming language by Microsoft. Though initially it was developed as part of .net but later it was approved by ECMA and ISO standards.

You can use C# to create variety of applications, like web, windows, mobile, console applications and much more using Visual studio.

Syntax help

Data types

Data TypeDescriptionRangesize
intTo store integers-2,147,483,648 to 2,147,483,6474 bytes
doubleto store large floating point numbers with decimalscan store 15 decimal digits8 bytes
floatto store floating point numbers with decimalscan store upto 7 decimal digits4 bytes
charto store single characters-2 bytes
stringto stores text-2 bytes per character
boolto stores either true or false-1 bit

Variables

Syntax

datatype variable-name = value;

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition or set of few conditions IF-ELSE is used.

if(conditional-expression) {
   // code
} 
else {
   // code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement) {
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

data-type[] array-name;

Methods

Method is a set of statements which gets executed only when they are called. Call the method name in the main function to execute the method.

Syntax

static void method-name() 
{
  // code to be executed
}