Chosen ciphertext correlation power analysis on Kyber.

The post-quantum cryptography (PQC) standardization process of the National Institute of Standards and Technology (NIST) has entered the final round. Kyber is one of the four key encapsulation mechanism (KEM) finalists. The coefficient multiplication is vulnerable to side-channel attacks. In this paper, we analyzed the multiplication part of Kyber and proposed the methods for constructing ciphertext. By using the chosen ciphertext, more functions can be attacked in the reference implementation of Kyber512. The attacks succeed on the pqm4 implementation with chosen ciphertext while failing with random ciphertext in our experiment environment. For all the attacks, the full secret key recovery can be achieved in a few minutes. • We used chosen ciphertext to attack more position in the decryption of Kyber. • The number of traces used for some functions was reduced by using chosen ciphertext. • In all the experiments, the proposed attack taked only several minutes. [ABSTRACT FROM AUTHOR]