Security Articles from Wikipedia

Cryptographic hash function 35
[10] Shai Halevi and Hugo Krawczyk, Randomized Hashing and Digital Signatures (http:/ / www. ee. technion. ac. il/ ~hugo/ rhash/ )
[11] NIST.gov - Computer Security Division - Computer Security Resource Center (http:/ / csrc. nist. gov/ groups/ ST/ hash/ sha-3/ index. html)
[12] http:/ / www. springerlink. com/ content/ 2514122231284103/
[13] http:/ / www. springerlink. com/ content/ n5vrtdha97a2udkx/
[14] http:/ / eprint. iacr. org/ 2008/ 089. pdf
[15] http:/ / www. springerlink. com/ content/ v6526284mu858v37/
[16] http:/ / eprint. iacr. org/ 2010/ 016. pdf
[17] http:/ / eprint. iacr. org/ 2009/ 223. pdf
[18] http:/ / springerlink. com/ content/ d7pm142n58853467/
[19] http:/ / eprint. iacr. org/ 2008/ 515
[20] http:/ / www. springerlink. com/ content/ 3810jp9730369045/
[21] http:/ / eprint. iacr. org/ 2008/ 469. pdf
[22] http:/ / www. springerlink. com/ content/ u762587644802p38/
Further reading
• Bruce Schneier. Applied Cryptography. John Wiley & Sons, 1996. ISBN 0-471-12845-7.
• Christof Paar, Jan Pelzl, "Hash Functions" (http:/ / wiki. crypto. rub. de/ Buch/ movies. php), Chapter 11 of
"Understanding Cryptography, A Textbook for Students and Practitioners". (companion web site contains online
cryptography course that covers hash functions), Springer, 2009.
Diffie–Hellman key exchange
Diffie–Hellman key exchange (D–H) [1] is a specific method of exchanging keys. It is one of the earliest practical
examples of key exchange implemented within the field of cryptography. The Diffie–Hellman key exchange method
allows two parties that have no prior knowledge of each other to jointly establish a shared secret key over an
insecure communications channel. This key can then be used to encrypt subsequent communications using a
symmetric key cipher.
The scheme was first published by Whitfield Diffie and Martin Hellman in 1976, although it later emerged that it
had been separately invented a few years earlier within GCHQ, the British signals intelligence agency, by Malcolm
J. Williamson but was kept classified. In 2002, Hellman suggested the algorithm be called Diffie–Hellman–Merkle
key exchange in recognition of Ralph Merkle's contribution to the invention of public-key cryptography (Hellman,
2002).
Although Diffie–Hellman key agreement itself is an anonymous (non-authenticated) key-agreement protocol, it
provides the basis for a variety of authenticated protocols, and is used to provide perfect forward secrecy in
Transport Layer Security's ephemeral modes (referred to as EDH or DHE depending on the cipher suite).
History of the protocol
The Diffie–Hellman key agreement was invented in 1976 during a collaboration between Whitfield Diffie and
Martin Hellman and was the first practical method for establishing a shared secret over an unprotected
communications channel. Ralph Merkle's work on public key distribution was an influence. John Gill suggested
application of the discrete logarithm problem. It had first been invented by Malcolm Williamson of GCHQ in the UK
some years previously, but GCHQ chose not to make it public until 1997, by which time it had no influence on
research in academia.
The method was followed shortly afterwards by RSA, another implementation of public key cryptography using
asymmetric algorithms.
In 2002, Martin Hellman wrote: