Algebraic Attacks on Stream Ciphers

Algebraic Attacks are a new powerful tool to cryptanalyse many stream ciphers previously believed very secure. All stream ciphers with linear feedback (one or several LFSR, linear cellular automata etc..) and a combiner are concerned, even if the combiner is stateful, and even if it is secret or key-dependent.

Here are some extended survey slides from 2002-2007 and here is an extended version from 2003 of one of the key papers in this area.

References - Algebraic attacks on stream ciphers:

References - How to avoid algebraic attacks on stream ciphers:

Interesting links:
Crypto Debates: The difficult question of strong cryptography
The AES 1 million dollar challenge (or why there should be such a thing)

Security of important ciphers used in practice: Security of DES
AES: is the new encryption standard already broken ?

New algebraic attacks on encrytion algorithms:
Algebraic attacks on block ciphers and AES

Algebraic attacks applied to stream ciphers
Positive applications of multivariate equations:
promoting/about multivariate cryptography:
The McEliece_based short signature scheme CFS
The HFE cryptosystem home page
The Minrank Zero-knowledge identification scheme
Quartz /Flash /Sflash signature schemes
Nicolas Courtois research page 
TTM cryptosystem, GPT cryptosystem,
Open Problems in Multivariate Cryptography (Stork Document)