Hash functions map binary strings of an arbitrary length to small binary strings of a fixed length.
The MD5 algorithm is a widely used hash function producing a 128-bit hash value (16 Bytes, 32 Hexdecimal characters).
The ComputeHash method of the System.Security.Cryptography.MD5 class returns the hash as an array of 16 bytes.
Example:
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
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.