The post-quantum key-encapsulation mechanism CRYSTALS-KYBER has been selected for standardization by the National Institute of Standards and Technology (NIST) under the name ML-KEM [1]. For implementations of cryptographic algorithms, side-channel attacks targeting the implementation pose a serious threat. Among others, such attacks can exploit timing, power or EM side-channels.

Recently two timing vulnerabilities have been presented under the name KyberSlash [2]. This work aims at analyzing the work presented in [2]. In that sense, the task is to analyze the exploited operations that enabled KyberSlash, and to explain the proposed countermeasure that mitigate the attack.

References:

• [1] https://csrc.nist.gov/pubs/fips/203/final
• [2] https://tches.iacr.org/index.php/TCHES/article/view/12046

Side-Channel attacks can be very powerful vulnerabilities on Edge- and IoT-Devices, they can reveal secret keys using just an oscilloscope. As an universal countermeasure, a random shuffling of the code executions has proven effective. However, on modern processor architectures, this is easier said than done.
One way to implement this is a polymorphic code: a program that can recompile at runtime, generating different machine code for the same task [1]. 

Target of this work is to summarize and compare several publications from recent years. Some background knowledge in informatics is recommended.

[1] Runtime Code Polymorphism as a Protection Against Side Channel Attacks, Damien Couroussé and Thierno Barry and Bruno Robisson and Philippe Jaillon and Olivier Potin and Jean-Louis Lanet, https://eprint.iacr.org/2017/699