Message Digest 5 (MD5)
Definition - What does Message Digest 5 (MD5) mean?
Message Digest 5 (MD5) is a hash function used in cryptography. Developed by Ronald Rivest in 1991, Message Digest 5 produces a 128-bit resulting hash value. Similar to other message-digest algorithms, it was largely developed for digital signature applications which make use of a large compressed file in a secure fashion.
Although it is still widely used, security of the function is severely compromised and as a result most applications, especially ones related to the U.S. government, require the SHA-2 family of hash functions for cryptography. Message Digest 5 is considered to be broken and unsuitable for further use according to the U.S. Department of Homeland Security.
Techopedia explains Message Digest 5 (MD5)
Details of the Message Digest 5 algorithm are provided in RFC 1321. The algorithm of Message Digest 5 makes use of a message of any length and outputs a 128-bit message digest of the input. The Message Digest 5 algorithm does not need any large substitution tables and is an extension of the Message Digest 4 algorithm. Compared to Message Digest 4, Message Digest 5 is more conservative in design but is slower. The steps involved in the Message Digest 5 algorithm are appending of padding bits, appending representation of padded message to the original message, initialization of message digest buffer, processing of message in 16-word blocks and finally outputting the result. Compared to Message Digest 4, Message Digest 5 is slightly more complex.
On a 32-bit machine, Message Digest 5 performs much faster compared to other message digest algorithms. Message Digest 5 is simple to implement when compared with similar digest algorithms. The difficulty of coming up with same message digest from two different messages are on the order of 264 operations.
Join thousands of others with our weekly newsletter
Free Whitepaper: The Path to Hybrid Cloud:
Free E-Book: Public Cloud Guide:
Free Tool: Virtual Health Monitor:
Free 30 Day Trial – Turbonomic: