VEST

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VEST

High Level Structure of VEST
General
Designers	Sean O'Neil
First published	June 13, 2005
Cipher detail
Key sizes	any
Security claims	80–256 bits
State size	256 bits (VEST-4) to 768 (VEST-32)
Structure	NLFSR, SPN, T-function

VEST (Very Efficient Substitution Transposition) ciphers are a set of families of general-purpose hardware-dedicated ciphers that support single pass authenticated encryption and can operate as collision-resistant hash functions designed by Sean O'Neil, Benjamin Gittins and Howard Landman.^[1] VEST cannot be implemented efficiently in software.

VEST is based on a balanced T-function that can also be described as a bijective nonlinear feedback shift register with parallel feedback (NLPFSR) or as a substitution–permutation network, which is assisted by a non-linear RNS-based counter. The four VEST family trees described in the cipher specification are VEST-4, VEST-8, VEST-16, and VEST-32. VEST ciphers support keys and IVs of variable sizes and instant re-keying. All VEST ciphers release output on every clock cycle.

All the VEST variants are covered by European Patent Number EP 1820295(B1), owned by Synaptic Laboratories.

VEST was a Phase 2 Candidate in the eSTREAM competition in the hardware portfolio, but was not a Phase 3 or Focus candidate and so is not part of the final portfolio.