Characteristic automated search of cryptographic algorithms for distinguishing attacks (CASCADA)

Abstract

Automated search methods based on Satisfiability Modulo Theory (SMT) problems are being widely used to evaluate the security of block ciphers against distinguishing attacks. While these methods provide a systematic and generic methodology, most of their software implementations are limited to a small set of ciphers and attacks, and extending these implementations requires significant effort and expertise. In this work, the authors present cryptographic algorithms for distinguishing attacks (CASCADA), an open-source Python library to evaluate the security of cryptographic primitives, specially block ciphers, against distinguishing attacks with bit-vector SMT solvers. The tool CASCADA implements the bit-vector property framework herein proposed and several SMT-based automated search methods to evaluate the security of ciphers against differential, relatedkey differential, rotational-XOR, impossible-differential, impossible-rotational-XOR, related-key impossible-differential, linear and zero-correlation cryptanalysis. The library CASCADA is the result of a huge engineering effort, and it provides many functionalities, a modular design, an extensive documentation and a complete suite of tests.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

A CP-Based Automatic Tool for Instantiating Truncated Differential Characteristics

“…The idea of a simple tool to perform differential analysis is interesting, and other recent works are also working in this direction [26,2]. Moreover, we think that a unified cipher format would help the comparison and development of these tools.…”

A Cipher-Agnostic Neural Training Pipeline with Automated Finding of Good Input Differences

“…Declarative approaches (MILP, SAT, SMT, CP...) have since then become the de facto standard for differential cryptanalysis. More recently, open-source cryptographic libraries such as Tagada [LDLS21], Cascada [RR22] or CLAASP [BGG + 23] have made the process fully automated: from the description of a cipher, these libraries build and solve the declarative models for the search of optimal differential characteristics, without human intervention. A similar slow automation process was followed for other techniques, such as linear or impossible differential cryptanalysis, which are implemented within these libraries as well.…”