Paper 2017/220
Cryptanalysis of PMACx, PMAC2x, and SIVx
Kazuhiko Minematsu and Tetsu Iwata
Abstract
At CT-RSA 2017, List and Nandi proposed two variable input length pseudorandom functions (VI-PRFs) called PMACx and PMAC2x, and a deterministic authenticated encryption scheme called SIVx. These schemes use a tweakable block cipher (TBC) as the underlying primitive, and are provably secure up to the query complexity of $2^n$, where $n$ denotes the block length of the TBC. In this paper, we falsify the provable security claims by presenting concrete attacks. We show that with the query complexity of $O(2^{n/2})$, i.e., with the birthday complexity, PMACx, PMAC2x, and SIVx are all insecure.
Metadata
- Available format(s)
- Category
- Secret-key cryptography
- Publication info
- Published by the IACR in FSE 2018
- Keywords
- CryptanalysisPMACxPMAC2xSIVxprovable security
- Contact author(s)
- k-minematsu @ ah jp nec com
- History
- 2017-06-07: revised
- 2017-03-04: received
- See all versions
- Short URL
- https://ia.cr/2017/220
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2017/220, author = {Kazuhiko Minematsu and Tetsu Iwata}, title = {Cryptanalysis of {PMACx}, {PMAC2x}, and {SIVx}}, howpublished = {Cryptology {ePrint} Archive, Paper 2017/220}, year = {2017}, url = {https://eprint.iacr.org/2017/220} }