Paper 2020/734

Mirror Theory: A simple proof of the Pi+Pj Theorem with xi_max=2

Benoît Cogliati and Jacques Patarin

Abstract

We provide a simple and complete proof of the famous Pi⊕Pj Theorem in the particular case where ξmax=2. This Theorem gives a lower bound for the number of solutions of simple linear systems of equations in the case where all the variables have to be pairwise distinct. Such systems often occur in cryptographic proofs of security, and this particular Theorem can be used to prove that the function x↦P(0||x)⊕P(1||x) is an optimally secure pseudorandom function when P is a uniformly random permutation.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint. MINOR revision.
Keywords
Mirror Theorysecurity proofsoptimal security
Contact author(s)
benoitcogliati @ hotmail fr
History
2020-06-18: received
Short URL
https://ia.cr/2020/734
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2020/734,
      author = {Benoît Cogliati and Jacques Patarin},
      title = {Mirror Theory: A simple proof of the Pi+Pj Theorem with xi_max=2},
      howpublished = {Cryptology ePrint Archive, Paper 2020/734},
      year = {2020},
      note = {\url{https://eprint.iacr.org/2020/734}},
      url = {https://eprint.iacr.org/2020/734}
}
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