MD5 Information

The MD5 (Message-Digest algorithm 5) algorithm was created by a professor named Ronald L. Rivest of MIT. Using this algorithm you are able to calculate a hash value or digest of any message. A digest works as a fingerprint for the text that you apply the algorithm on. A fingerprint has the length of 128-bit and is often written as a charactersting of 32 hex digits. The internals is specified in rfc1321. The beautiful thing about this hash value is that it is almost impossible to produce two messages that will result in the same digest or hash siquence of bits. Thus it is often used when comparing large amounts of data.

It is widely used by publishers of downloadable material on the internet to ensure the authenticy of the downloaded content. To do so the publisher supplies the hash value together with the download link to the file. The user is then able to compare the two values after download by calculating the MD5 hash value of the downloaded file. There are some utilities avaliable on the Internet for free download that will calculate these digests.

RSA's MD5 disclaimer

Public Information Sources

MD5 - Wikipedia, the free encyclopedia

MD5 Tools

I have collected a short list of MD5 tools and utilities on this page so that you can download the one that suits your task at hand.

Windows

MD5 Calculator: Right any file to calculate and compare the hash value.
MD5sums 1.2: Generate MD5 hashes of files (with progress indicator).
Advanced CheckSum Verifier (ACSV) v1.5.0: Comprehensive SFV and MD5 checksum utility with GUI for Windows 95/98/Me/NT/2000/XP/2003.
FastSum: MD5 checksum utility for Windows.
md5: Command Line Message Digest Utility.

Unix

md5: Command Line Message Digest Utility.

SQL Server

Microsoft SQL Server 2000: MD5 Hash SQL Server Extended Stored Procedure

Visual Basic (VB)

MD5 Class by Robert Hubley: MD5 class that wraps a MD5.DLL file written C++.
MD5 Digest: VB, VBScript (ASP), and JavaScript versions

Java Script (JScript)

Paj's Home: MD4, MD5 and SHA-1 algorithms.
Java Version by Thomas Weber: A Java implementation of the RSA Data Security, Inc. MD5 Message

TCL

MD5 message-digest algorithm: Implementation in Tcl of the MD5 message-digest algorithm as described in RFC 1321 (1).