Received Oct 5 th , 2012 Accepted Oct 30 th , 2012 Using more than two factors in the modulus of the RSA cryptosystem has the arithmetic advantage that the private key computation can be speeded up by CRT. With this idea, we present an efficient combination of two variants of RSA cryptosystem (Batch and Mprime RSA) which makes the decryption process faster than the existing variants. It can not...

We report a break for a recently proposed class of cryptosystems. The cryptosystem uses constant points of a periodic secret orbit to encrypt the plaintext. In order to break the system, it suffices to sort the constant points and find the initial fixed point. We also report breaks for the modified versions of the cryptosystem. Besides, we discuss some efficiency issues of the the cryptosystem.

At the 1990 EuroCrypt Conference, Niemi proposed a new public-key cryptosystem based on modular knapsacks. Y.M. Chee in Singapore, A. Joux and J. Stern in Paris independently found that this cryptosystem is insecure. Our two cryptanalytic methods are slightly different, but they are both based on the LLL algorithm. This is one more example of a cryptosystem that can be broken using this powerfu...

We show a new cryptosystem based on non-commutativ calculations of matrices, more specially nilpotent matrices. The cryptosystem seems powerful to restsist against usual attacks.

McEliece cryptosystem is a public-key cryptosystem based on error-correcting codes. It constitutes one of the few alternatives to cryptosystems relying on number theory. We present a modification of the McEliece cryptosystem which strengthens its security without increasing the size of the public key. We show that it is possible to use some properties of the automorphism groups of the codes to ...

Sub-optimal infant and young child feeding (IYCF) practices are likely a significant contributor to high undernutrition rates in Viet Nam. To date, however, there has been no comprehensive review of IYCF practices in Viet Nam. The objectives of this paper were to review: 1) patterns/trends in IYCF in Viet Nam; 2) the barriers and facilitators to IYCF practices; and 3) interventions and policies...

Nicotinamide (NAM), a form of vitamin B3, is a byproduct and noncompetitive inhibitor of the deacetylation reaction catalyzed by Sirtuins. These represent a family of evolutionarily conserved NAD+-dependent deacetylases that are well-known critical regulators of metabolism and aging and whose founding member is Sir2 of Saccharomyces cerevisiae. Here, we investigated the effects of NAM supplemen...