International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Jae Woo Han

Publications

Year
Venue
Title
2004
FSE
2003
EPRINT
Algebraic Attacks on Summation Generators
We apply the algebraic attacks on stream ciphers with memories to the summation generator. For a summation generator that uses $n$ LFSRs, the algebraic equation relating the key stream bits and LFSR output bits can be made to be of degree less than or equal to $2^{\lceil\log_2 n \rceil}$, using $\lceil\log_2 n \rceil + 1$ consecutive key stream bits. This is much lower than the upper bound given by previous general results.
2002
EPRINT
Key recovery attacks on NTRU without ciphertext validation routine
NTRU is an efficient public-key cryptosystem proposed by Hoffstein, Pipher, and Silverman. Assuming access to a decryption oracle, we show ways to recover the private key of NTRU systems that do not include a ciphertext validating procedure. The strongest of our methods will employ just a single call to the oracle, and in all cases, the number of calls needed will be small enough to be realistic.
2001
ASIACRYPT
2000
CRYPTO