Work

Generalizations of ChiChi: Families of Low-Latency Permutations in Any Even Dimension

Year: 2025

Type: article

Abstract: At Eurocrypt’25, Belkheyar et al. introduced a new non-linear layer called ChiChi or χχ. ChiChi is built based on Daemen’s χ function, but crucially gives a permutation in even dimension divisible by four.In this work, we generalize their construction in multiple ways, prove their open conjecture regarding the algebraic degree of the inverse of ChiChi, and investigate the properties of it against key recovery attacks.

Source: IACR Transactions on Symmetric Cryptology

DOI: 10.46586/tosc.v2025.i3.800-826

Authors: Samuele Andreoli, Gregor Leander, Enrico Piccione, Lukas Stennes

Institutions: University of Bergen, Ruhr University Bochum

Language: English

Topic: Cryptographic Implementations and Security

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: diamond

Funders: Deutsche Forschungsgemeinschaft, Norges Forskningsråd, HORIZON EUROPE European Research Council

Awards: EXC 2092: CyberSicherheit im Zeitalter großskaliger Angreifer (CASA), Trust-by-Design – Strong Security Arguments for Symmetric Key Cryptography