Low-density attack revisited

A New Knapsack Public-Key Cryptosystem Based on Permutation Combination Algorithm

A new secure knapsack cryptosystem based on the Merkle-Hellman public key cryptosystem will be proposed in this paper. Although it is common sense that when the density is low, the knapsack cryptosystem turns vulnerable to the low-density attack. The density d of a secure knapsack cryptosystem must be larger than 0 9408 . to avoid low-density attack. In this paper, we investigate a new Permutat...

On the Definitions of Cryptographic Security: Chosen-Ciphertext Attack Revisited

Low Secret Exponent RSA Revisited

We present a lattice attack on low exponent RSA with short secret exponent d = N for every δ < 0.29. The attack is a variation of an approach by Boneh and Durfee [4] based on lattice reduction techniques and Coppersmith’s method for finding small roots of modular polynomial equations. Although our results are slightly worse than the results of Boneh and Durfee they have several interesting feat...

Bauer-Berson-Feiertag attack revisited

We show that Shoup and Rubin’s protocols are not secure against the BBF attack proposed by Bauer, Berson, and Feiertag, and propose an amendment. Furthermore, our results indicate that both Bellare and Rogaway’s security and Paulson’s security do not imply the security against the BBF attack.

Cryptanalysis of a New Knapsack Type Public-Key Cryptosystem

— Recently, Hwang et al. introduced a knapsack type public-key cryptosystem. They proposed a new algorithm called permutation combination algorithm. By exploiting this algorithm, they attempt to increase the density of knapsack to avoid the low-density attack. We show that this cryptosystem is not secure, as it based on basic Merkel-Hellman knapsack cryptosystem and because of the superincreasi...