Paper 2022/1123
DEEPAND: In-Depth Modeling of Correlated AND Gates for NLFSR-based Lightweight Block Ciphers
Abstract
Automated cryptanalysis has taken center stage in the arena of cryptanalysis since the pioneering work by Mouha et al. which showcased the power of Mixed Integer Linear Programming (MILP) in solving cryptanalysis problems that otherwise, required significant effort. Since its inception, research in this area has moved in primarily two directions. One is to model more and more classical cryptanalysis tools as optimization problems to leverage the ease provided by state-of-the-art solvers. The other direction is to improve existing models to make them more efficient and/or accurate. The current work is an attempt to contribute to the latter. In this work, a general model referred to as DEEPAND has been devised to capture the correlation between AND gates in NLFSR-based lightweight block ciphers. DEEPAND builds upon and generalizes the idea of joint propagation of differences through AND gates captured using refined MILP modeling of TinyJAMBU by Saha et al. in FSE 2020. The proposed model has been applied to TinyJAMBU and KATAN and can detect correlations that were missed by earlier models. This leads to more accurate differential bounds for both ciphers.
In particular, a 384-round (full-round as per earlier specification) Type-IV trail is found for TinyJAMBU with 14 active AND gates using the new model, while the refined model reported this figure to be 19. This also reaffirms the decision of the designers to increase the number of rounds from 384 to 640. Moreover, the model succeeds in searching a full round Type-IV trail of TinyJAMBU keyed permutation
Metadata
- Available format(s)
-
PDF
- Category
- Attacks and cryptanalysis
- Publication info
- Preprint.
- Keywords
- MILPKATANTinyJAMBUSymmetric-Key Cryptanalysis
- Contact author(s)
-
janaamit001 @ gmail com
mrahman454 @ gmail com
dhiman @ iitbhilai ac in - History
- 2023-03-02: last of 2 revisions
- 2022-08-29: received
- See all versions
- Short URL
- https://ia.cr/2022/1123
- License
-
CC0
BibTeX
@misc{cryptoeprint:2022/1123, author = {Amit Jana and Mostafizar Rahman and Dhiman Saha}, title = {{DEEPAND}: In-Depth Modeling of Correlated {AND} Gates for {NLFSR}-based Lightweight Block Ciphers}, howpublished = {Cryptology {ePrint} Archive, Paper 2022/1123}, year = {2022}, url = {https://eprint.iacr.org/2022/1123} }