Paper 2015/504

The Iterated Random Permutation Problem with Applications to Cascade Encryption

Brice Minaud and Yannick Seurin

Abstract

We introduce and study the iterated random permutation problem, which asks how hard it is to distinguish, in a black-box way, the r-th power of a random permutation from a uniformly random permutation of a set of size N. We show that this requires Omega(N) queries (even for a two-sided, adaptive adversary). As a direct application of this result, we show that cascading a block cipher with the same key cannot degrade its security (as a pseudorandom permutation) more than negligibly.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
A minor revision of an IACR publication in CRYPTO 2015
Keywords
iterated random permutation problemblock cipherpseudorandom permutationcascade encryption
Contact author(s)
brice minaud @ gmail com
History
2015-05-27: received
Short URL
https://ia.cr/2015/504
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2015/504,
      author = {Brice Minaud and Yannick Seurin},
      title = {The Iterated Random Permutation Problem with Applications to Cascade Encryption},
      howpublished = {Cryptology ePrint Archive, Paper 2015/504},
      year = {2015},
      note = {\url{https://eprint.iacr.org/2015/504}},
      url = {https://eprint.iacr.org/2015/504}
}
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