An automated model for differential meet in the middle attacks on AndRX ciphers

Area of Science:

• Cryptography
• Computer Science
• Information Security

Background:

• Differential meet-in-the-middle (MITM) techniques are crucial for block cipher cryptanalysis.
• Manual identification of these attacks on large, bit-oriented ciphers is complex and error-prone.

Purpose of the Study:

• To develop an automated framework for systematically searching and optimizing differential MITM attacks.
• To enhance the efficiency and applicability of these attacks on AndRX-based block ciphers.

Main Methods:

• A constraint-based formulation to identify optimal single-key differential characteristics.
• A unified bitwise constraint programming (CP) model for constructing optimized differential MITM attacks.
• Incorporation of equivalent subkey, selective key guessing, parallel partitioning, and reducing data techniques.

Main Results:

• The framework successfully automates differential MITM attack construction for AndRX ciphers.
• Enhanced key recovery efficiency and extended round coverage for SIMON and Simeck families.
• Demonstrated practicality and generality of the automated approach on bit-oriented block ciphers.

Conclusions:

• The automated framework significantly improves the efficiency and scope of differential MITM cryptanalysis.
• The bit-level, generic design allows application to various bit-oriented block ciphers beyond AndRX.
• This work highlights the importance of automation in modern cryptanalysis.