International Association for Cryptologic Research (IACR)
Abstract
In this paper security aspects of the existing symmetric key encryption schemes based on Hadamard matrices are examined. Hadamard matrices itself have symmetries like one circulant core or two circulant core. Here, we are exploiting the inherent symmetries of
Hadamard matrices and are able to perform attacks on these encryption schemes. It is found that entire key can be obtained by observing the ciphertext
