Definition of digital signatures. Recall that we had the following picture: Private Key Public Key Secrecy Private Key Encryption Public key Encryption Integrity Message Authentication Codes (MAC) ?? Digital signatures complete this picture by giving a public key analog of message authentication codes. Digital signatures were suggested by Diffie and Hellman in their seminal paper, but unlike th...

In this paper I describe and extend a new DNA computing paradigm introduced in Blumberg [4] for building massively parallel machines in the DNA-computing models described by Adelman [1, 2], Cai et. al.[5], and Liu et. al.[8]. Employing only DNA operations which have been reported as successfully performed, I present an implementation of a Connection Machine [7], a SIMD (single-instruction multi...

In 1994, University of Southern California computer scientist Dr. Leonard Adelman solved the Hamiltonian Path Problem using DNA as a computational mechanism. He proved the principle that DNA computing could be used to solve computationally complex problems. Because of the limitations in discovery time, resource requirements, and sequence mismatches, DNA computing has not yet become a commonly a...

The Orbit Problem consists of determining, given a matrix A ∈ Rd×d and vectors x, y ∈ R, whether there exists n ∈ N such that A = y. This problem was shown to be decidable in a seminal work of Kannan and Lipton in the 1980s. Subsequently, Kannan and Lipton noted that the Orbit Problem becomes considerably harder when the target y is replaced with a subspace of R . Recently, it was shown that th...

We consider the problem of proving circuit lower bounds against the polynomialtime hierarchy. We give both positive and negative results. For the positive side, for any fixed integer k > 0, we give an explicit Σp2 language, acceptable by a Σ p 2-machine with running time O(nk 2 log n), that requires circuit size > nk. This provides a constructive version of an existence theorem of Kannan [Kan82...

The problem of finding the prime factors of large composite numbers has always been of mathematical interest. With the advent of public key cryptosystems it is also of practical importance, because the security of some of these cryptosystems, such as the Rivest-Shamir-Adelman (RSA) system, depends on the difficulty of factoring the public keys. In recent years the best known integer factorisati...

Tracking the moving objects in high traffic environment is really a complex task. For location tracking system Spatial Data values are used. The information regarding the location of the objects is maintained by Database Server. To process Spatial Query values the application server is used. Location update is the highly bandwidth and resource constrained operation in the moving object tracking...

Decision support systems refer to interactive computer-based systems which help decision-makers to make a decision. Evaluation of a decision support system, that is, the act of measuring its quality characteristics, is an essential component of its design and development if considered an integral part of it and not employed at the end of its completion. In fact, evaluation permits to keep the d...

Introduction: A composite index (or simply an index) is constructed with an objective to obtain a synoptic or comprehensive single number, representing a vast array of measurements on the multiple aspects of a ‘conceptual entity’ such as general price level, cost of living, level of economic development and regional disparities (Adelman and Morris, 1967; Pal, 1975; Mishra and Chopra, 1978; Mish...

In September 1996 Boneh, Demillo, and Lipton from Bellcore announced a new type of cryptanalytic attack which exploits computational errors to find cryptographic keys. Their attack is based on algebraic properties of modular arithmetic, and thus it is applicable only to public key cryptosystems such as RSA, and not to secret key algorithms such as the Data Encryption Standard (DES) . In this pa...