PhD defence: Decryption Failure Attacks on Post Quantum Cryptography

Disputation

From: 2023-05-11 09:15 to 12:00
Place: E:A, E-huset, Ole Römers väg 3, LTH, Lund University, Lund, and online
Contact: thomas [dot] johansson [at] eit [dot] lth [dot] se

Thesis title: Decryption Failure Attacks on Post Quantum Cryptography

Author: Alexander Nilsson, Department of Electrical and Information Technology, Lund University

Faculty opponent:  Professor Markku-Juhani Saarinen, Finland

Location: E:A, E-huset, Ole Römers väg 3, LTH, Lund University, Lund.

Streamed at:  https://lu-se.zoom.us/s/67941251689

Thesis at LU Research Portal

Abstract

The evaluation of next generation of public-key encryption and digital signature algorithms are ongoing, with much at stake. The hope is that these algorithms will be secure for many, many years after their initial deployment. In fact they are expected to remain secure even in the face of fully developed and functional Quantum Computers (QCs). It is well known within the research community that QCs will break some of the most important and widespread algorithms that we otherwise use today. Replacements must be standardized well before QCs are realized. This field is called Post-Quantum Cryptography (PQC). The research included in this dissertation relates to cryptanalysis of several candidate PQC schemes. In one case a proposed alternative decoder is proposed for one of the schemes. Other results pertain to implementation issues of some of the new proposed schemes. Some attacks found in literature have been improved upon with new techniques. And some attacks are novel and affects the source code implementation of the schemes. We argue that our novel attacks are general and affect many different schemes and we show the applicability of the attacks by implementing them against some of them.