The development of Public Key Infrastructures (PKIs) is highly desirable to support secure digital transactions and communications throughout existing networks. It is important to adopt a particular trust structure or PKI model at an early stage as this forms a basis for the PKI’s development. Many PKI models have been proposed but use only natural language descriptions. We apply a simple forma...

This paper gives an overview of the research that has been done on computing on encrypted data, namely fully homomorphic encryption (FHE) and functional encryption (FE). We first describe public-key encryption schemes and then provide a background and motivation for FHE and FE. We then outline the ideas of the FHE and FE encryption schemes and security. We also tested the performance of a curre...

This paper takes advantages of the symmetrical key and asymmetrical key technologies, and proposes a key distribution scheme based on public key cryptography. This scheme does not need to pre-distribute pair-wise keys. Pair-wise key is set up between two nodes after deployment according to a specific route algorithm. The scheme is able to guarantee there is a direct pair-wise key between two no...

The paper cryptanalyses a public-key cryptosystem recently proposed by Grigoriev and Ponomarenko, which encrypts an element from a fixed finite group defined in terms of generators and relations to produce a ciphertext from SL(2, Z). The paper presents a heuristic method for recovering the secret key from the public key, and so this cryptosystem should not be used in practice.

This paper introduces the XTR public key system. XTR is based on a new method to represent elements of a subgroup of a multiplicative group of a finite field. Application of XTR in cryptographic protocols leads to substantial savings both in communication and computational overhead without compromising security.

In choosing between different public-key encryption schemes, the two most important issues to consider are (1) security and (2) cost (practicality). The latter issue is readily quantified and most experts can agree on which systems are likely to offer performance advantages. Our purpose in this note is to clarify the primary considerations involved in analyzing security, as assessing the securi...

The unicity distance, U, of a secret-key cipher is defined by Shannon as the minimum amount of intercepted ciphertext symbols needed, in principle, to uniquely determine the secret key and, therefore, break the cipher. Accordingly, for a ciphertext of size N symbols less than U, the estimated key will have a nonzero probability of error. Of interest is knowing the chance or probability that an ...

Research on sensor networks has become much more active and is currently being applied to many different fields. However since sensor networks are limited to only collecting and reporting information regarding a certain event, and requires human intervention with that given information, it is often difficult to react to an event or situation immediately and proactively. To overcome this kind of...

Braid cryptosystem was proposed in CRYPTO 2000 as an alternate public-key cryptosystem. The security of this system is based upon the conjugacy problem in braid groups. Since then, there have been several attempts to break the braid cryptosystem by solving the conjugacy problem in braid groups. In this paper, we first survey all the major attacks on the braid cryptosystem and conclude that the ...