Turing (cipher)

Turing is a stream cipher developed by Gregory G. Rose and Philip Hawkes at Qualcomm for CDMA.<ref name=":3">Gregory G. Rose and Philip Hawkes, Turing: A Fast Stream Cipher, Fast Software Encryption 2003, pp. 290–306 (PDF).</ref>

Turing generates 160 bits of output in each round by applying a non-linear filter to the internal state of an LFSR. It is named after Alan Turing.<ref name=":3" /> It was developed based on the SOBER cipher introduced by Rose in 1998.<ref name=":0">Template:Cite book</ref> This is evident in its major component, the Linear Feedback Shift Register (LFSR), which is the same technology found in the family of SOBER machines.<ref name=":2">Template:Cite book</ref> Turing, however, is distinguished from its predecessors by the way it produces five words (five times more) of output for every internal update.<ref name=":0" /> It also provides up to 256-bit key strength and is designed to be fast in software,<ref name=":2" /> achieving around 5.5 cycles/byte on some x86 processors.

There are experts who found that the Turing stream cipher has a number of weaknesses when faced with chosen IV attacks.<ref name=":1">Template:Cite book</ref> For instance, its key scheduling algorithm has the same secret key for different initialization vectors and this is found to lower the system's security.<ref name=":1" />

See also

• SOBER-128
• Helix

Bibliography

• Antoine Joux and Frédéric Muller, A Chosen IV Attack Against Turing, Selected Areas in Cryptography 2003, pp. 194–207 (PDF).

External links

• Optimized Java implementation of Turing algorithm
• Java Implementation of Turing Algorithm
• Turing: a Fast Stream Cipher
• Slides and C reference implementation at Qualcomm