5,752 research outputs found
Cryptanalysis of a chaotic block cipher with external key and its improved version
Recently, Pareek et al. proposed a symmetric key block cipher using multiple
one-dimensional chaotic maps. This paper reports some new findings on the
security problems of this kind of chaotic cipher: 1) a number of weak keys
exists; 2) some important intermediate data of the cipher are not sufficiently
random; 3) the whole secret key can be broken by a known-plaintext attack with
only 120 consecutive known plain-bytes in one known plaintext. In addition, it
is pointed out that an improved version of the chaotic cipher proposed by Wei
et al. still suffers from all the same security defects.Comment: 14 pages, 2 figures, 1 table, formatted with elsart.cl
- …