Cryptology ePrint Archive: Report 2020/210

SITM: See-In-The-Middle--Side-Channel Assisted Middle Round Differential Cryptanalysis on SPN Block Ciphers

Shivam Bhasin and Jakub Breier and Xiaolu Hou and Dirmanto Jap and Romain Poussier and Siang Meng Sim

Abstract: Side-channel analysis constitutes a powerful attack vector against crypto- graphic implementations. Techniques such as power and electromagnetic side-channel analysis have been extensively studied to provide an efficient way to recover the secret key used in cryptographic algorithms. To protect against such attacks, countermea- sure designers have developed protection methods, such as masking and hiding, to make the attacks harder. However, due to significant overheads, these protections are sometimes deployed only at the beginning and the end of encryption, which are the main targets for side-channel attacks.

In this paper, we present a methodology for side-channel assisted differential crypt- analysis attack to target middle rounds of block cipher implementations. Such method presents a powerful attack vector against designs that normally only protect the beginning and end rounds of ciphers. We generalize the attack to SPN based ciphers and calculate the effort the attacker needs to recover the secret key. We provide experimental results on 8-bit and 32-bit microcontrollers. We provide case studies on state-of-the-art symmetric block ciphers, such as AES, SKINNY, and PRESENT. Furthermore, we show how to attack shuffling-protected implementations.

Category / Keywords: secret-key cryptography / Side-channel analysis, middle rounds attack, substitution-permutation network (SPN), differential cryptanalysis.

Original Publication (in the same form): IACR-CHES-2020

Date: received 18 Feb 2020

Contact author: sbhasin at ntu edu sg

Available format(s): PDF | BibTeX Citation

Version: 20200219:164526 (All versions of this report)

Short URL:

[ Cryptology ePrint archive ]