Cryptanalysis of ITRU
This work addresses a problem for cryptographers and security practitioners by exposing weaknesses in a proposed cryptosystem, though it is incremental as it builds on known attack methods.
The authors tackled the security of the ITRU cryptosystem, a variant of NTRU, by developing a frequency analysis attack that successfully breaks it, demonstrating vulnerabilities in its design.
ITRU cryptosystem is a public key cryptosystem and one of the known variants of NTRU cryptosystem. Instead of working in a truncated polynomial ring, ITRU cryptosystem is based on the ring of integers. The authors claimed that ITRU has better features comparing to the classical NTRU, such as having a simple parameter selection algorithm, invertibility, and successful message decryption, and better security. In this paper, we present an attack technique against the ITRU cryptosystem, and it is mainly based on a simple frequency analysis on the letters of ciphertexts.