Cryptology ePrint Archive: Report 2017/101
Optimizing Implementations of Lightweight Building Blocks
Jérémy Jean and Thomas Peyrin and Siang Meng Sim
Abstract: We study the synthesis of small functions used as building blocks in lightweight cryptographic designs in terms of hardware implementations. This phase most notably appears during the ASIC implementation of cryptographic primitives. The quality of this step directly affects the output circuit, and while general tools exist to carry out this task, most of them belong to proprietary software suites and apply heuristics to any size of functions. In this work, we focus on small functions (4- and 8-bit mappings) and look for their optimal implementations on a specific weighted instructions set which allows fine tuning of the technology.
We propose a tool named LIGHTER, based on two related algorithms, that produce optimized implementations of small functions. To demonstrate the validity and usefulness of our tool, we applied it to two practical cases: first, linear permutations that define diffusion in most of SPN ciphers; second, non-linear 4-bit permutations that are used in nearly all modern lightweight block ciphers. For linear permutations, we exhibit several new MDS diffusion matrices lighter than the state-of-the-art, and we also decrease the implementation cost of several already known MDS matrices. As for non-linear permutations, LIGHTER outperforms the area-optimized synthesis of the state-of-the-art academic tool ABC. Smaller circuits can also be reached when ABC and LIGHTER are used jointly.
Category / Keywords: implementation / LIGHTER, Implementation, ASIC, Lightweight Block Ciphers, Boolean function, Meet-in-the-Middle, Sbox, MDS Matrix
Date: received 9 Feb 2017
Contact author: ssim011 at e ntu edu sg
Available format(s): PDF | BibTeX Citation
Version: 20170213:193759 (All versions of this report)
Short URL: ia.cr/2017/101
Discussion forum: Show discussion | Start new discussion
[ Cryptology ePrint archive ]