Tietotekniikan seminaari: Symmetric Cryptography: Cryptanalysis and Design

Symmetric Cryptography: Cryptanalysis and Design

Qingju Wang
University of Glasgow
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Monday, 21 March at 10:15
via Zoom: request the link by email [email protected]
Note! the link will be sent by email to CS staff.

Abstract: Symmetric cryptography receives more and more attention as its role in cryptographic protocols such as multi-party computation or zero-knowledge proof systems. Cryptanalysis and design of symmetric-key ciphers is a highly technical, time-consuming and error-prone process. The first part of this talk introduces some advanced symmetric-key cryptanalysis methods aided by constraint programming automatic tools. The complexity of the aforesaid protocols is linked to that of the arithmetic representation of computation as a series of finite field operations. Consequently, there is a high demand for hash functions with an efficient arithmetization. We give an accurate cost metric description of symmetric primitives in zero-knowledge proof and propose a new design strategy.

Bio: Qingju Wang is a Postdoc researcher at the University of Luxembourg. Prior to that, she worked at the Technical University of Denmark and got her PhD from COSIC, KU Leuven. She is interested in all forms of symmetric cryptanalysis. Qingju co-invented Mixed Integer Linear Programming automatic tools, which have become the standard for symmetric cryptanalysis. Her proposals of new algebraic cryptanalysis lead to the full break of several ciphers such as LowMC and MiMC. Besides, her contribution to the theory of division property keeps the record of attacks on several stream ciphers. Another research focus of her is the design of authenticated encryption, and as part of this effort, her design SPARKLE becomes one of the finalists of the NIST lightweight crypto standardization process.