Visual Basic 2008 Recipes: A Problem-Solution Approach

12.13. Calculate the Hash Code of a Password

Problem

You need to store a user's password securely so that you can use it to authenticate the user in the future.

Solution

Create and store a cryptographic hash code of the password using a hashing algorithm class derived from the System.Security.Cryptography.HashAlgorithm class. On future authentication attempts, generate the hash of the password entered by the user and compare it to the stored hash code.

How It Works

Hashing algorithms are one-way cryptographic functions that take plaintext of variable length and generate a fixed-size numeric value. They are one-way because it's nearly impossible to derive the original plaintext from the hash code. Hashing algorithms are deterministic; applying ...