Using MD5 Hash Algorithm


In this post on Using MD5 Hash Algorithm, I will explain the MD5 algorithm for computing hash code, the MD5 abstract class in .NET, and its implementation for computing hash code.

Basically, the Message Digest algorithm named MD5 generates a 16-byte (128-bit) hash code. This algorithm is available with the MD5 class in ASP.NET. Further, the namespace System.Security.Cryptography defines this class.

Hash Function

As a matter of fact, a hash function can compute a fixed-length small binary string known as hash code from an arbitrary text of any size. Moreover, if there is a slight change in input strings, the hash code for both is totally different. In other words, for any two input strings, it is computationally infeasible to get the same hash code.

MD5CryptoServiceProvider Class

Since the MD5 class is an abstract class, all implementations of the MD5 algorithm inherit this class. In fact, MD5CryptoServiceProvider class is inherited from the MD5 class. Also, this class is declared as sealed class and can not be inherited further.

In order to generate a hash code, this class contains a method known as ComputeHash() that returns a 16-byte hash code. The following example shows how to retrieve the hash code for an input text using this function.

Generating Hash Code Using MD5 Hash Algorithm


<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="MD5Example.WebForm1" %>

<!DOCTYPE html>

<html xmlns="">
<head runat="server">
    <form id="form1" runat="server">
            Enter some text:<br />
            <br />
            <asp:TextBox ID="TextBox1" runat="server" Columns="50" Rows="10" TextMode="MultiLine"></asp:TextBox>
            <br />
            <br />
            <hr />
            <asp:Button ID="Button2" runat="server" Text="Get Text Size" OnClick="Button2_Click" />
            <asp:Label ID="Label2" runat="server" Text=""></asp:Label>
            <br />
            <br />
            <asp:Button ID="Button1" runat="server" Text="Get Hash Code" OnClick="Button1_Click" />
            <br />
            <hr />
            Computed Hash Code using MD5 algorithms for above text:<br />
            <br />
            <asp:Label ID="Label1" runat="server" Text=""></asp:Label>


using System;
using System.Security.Cryptography;
using System.Text;
namespace MD5Example
    public partial class WebForm1 : System.Web.UI.Page
        protected void Page_Load(object sender, EventArgs e)


        protected void Button1_Click(object sender, EventArgs e)
            String s1, s2;
            s1 = TextBox1.Text;

            s2 = GenerateHashCodeUsingMD5(s1);
            Label1.Text = s2;

        public String GenerateHashCodeUsingMD5(string s)
            StringBuilder str = new StringBuilder();
            MD5CryptoServiceProvider prv = new MD5CryptoServiceProvider();
            byte[] bytedata;
            bytedata=prv.ComputeHash(new UTF8Encoding().GetBytes(s));
            for(int i=0;i<bytedata.Length;i++)
            return str.ToString();

        protected void Button2_Click(object sender, EventArgs e)
            String str = TextBox1.Text;
            int size = str.Length;
            Label2.Text = "Total Characters: " + size;


Hash Code Generated Using MD5 Hash Algorithm
Hash Code Generated Using MD5 Hash Algorithm

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Example of Button and Link Button Control in ASP.NET

Example of Chart Control in ASP.NET

Creating a DataTable from a DataReader in ASP.NET

Deleting a Record using DataGrid Control in ASP.NET

Edit a Record Using DataGrid Control in ASP.NET

Insert a Record Using ItemCommand Event in DataGrid

CRUD Operations with DataGrid in ASP.NET

Creating Columns in a DataGrid Control

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Code Render Block in ASP.NET

ASP.NET Core Features and Advantages

Display Images Using DataList Control

Adding Images Using Image Control

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Example of Button Control in ASP.NET

Using MD5 Hash Algorithm

ItemDataBound Event in DataList

More Features of DataList in ASP.NET

A Simple Example of Using a DataList Control in ASP.NET

Properties and Methods of DataList Control in ASP.NET

ASP.NET Practice Exercise

Exploring DataList Control in ASP.NET

Custom Validator Control in ASP.NET

Validation Summary Control in ASP.NET

Validation Controls Examples – RequiredFieldValidator, CompareValidator, and RangeValidator

An Example of Data Binding with RadioButtonList Control

Binding Data to Web Control in ADO.NET

Examples of AdRotator Control in ASP.NET

Examples of Validation Controls in ASP.NET

Overview of MVC architecture in ASP.NET


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