Cryptographic hash algorithms produce fixed-length sequences based on input of arbitrary length. A given input always produces the same output, called a hash code. Using these algorithms, you can compute and validate hash codes to ensure that code running on your machine has not been tampered with or otherwise changed. ASP.NET provides a software mechanism for validating hash code fingerprints for every page requested by a client. In this article, the author shows how to use hash codes with ASP.NET applications to detect tampering and prevent malicious code from running when tampering is detected.
MSDN Magazine September 2002
View Complete Post