Hash functions map binary strings of an arbitrary length to small binary strings of a fixed length.

The [MD5](<https://en.wikipedia.org/wiki/MD5>) algorithm is a widely used hash function producing a 128-bit hash value (16 Bytes, 32 Hexdecimal characters).

The [ComputeHash](<https://msdn.microsoft.com/en-us/library/s02tk69a(v=vs.110).aspx>) method of the [System.Security.Cryptography.MD5](<https://msdn.microsoft.com/en-us/library/system.security.cryptography.md5(v=vs.110).aspx>) class returns the hash as an array of 16 bytes.


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

internal class Program
    private static void Main()
        var source = "Hello World!";

        // Creates an instance of the default implementation of the MD5 hash algorithm.
        using (var md5Hash = MD5.Create())
            // Byte array representation of source string
            var sourceBytes = Encoding.UTF8.GetBytes(source);

            // Generate hash value(Byte Array) for input data
            var hashBytes = md5Hash.ComputeHash(sourceBytes);

            // Convert hash byte array to string
            var hash = BitConverter.ToString(hashBytes).Replace("-", string.Empty);

            // Output the MD5 hash
            Console.WriteLine("The MD5 hash of " + source + " is: " + hash);

Output: The MD5 hash of Hello World! is: ED076287532E86365E841E92BFC50D8C

Security Issues:

Like most hash functions, MD5 is neither encryption nor encoding. It can be reversed by brute-force attack and suffers from extensive vulnerabilities against collision and preimage attacks.