Group key transfer protocols allow multiple parties to share a common secret key. They rely on a mutually trusted key generation center (KGC) that selects the key and securely distributes it to the authorized participants. Recently, Sun et al. proposed an authenticated group key transfer protocol based on secret sharing that they claim to be secure. We show that this is false: the protocol is s...

This paper revisits a public key cryptosystem which is based on finite string-rewriting systems. We consider a new approach for cryptanalysis of such proposals—the so-called completion attack. If a particular kind of weak key is generated, then a passive adversary is able to retrieve secret messages with a significant probability. Our idea can be applied to other rewriting based cryptosystems a...

This work uses enhanced symmetric key encryption algorithm, in which same structure of encryption and decryption procedure algorithm is used. In conventional encryption methods the key for encryption and decryption is same and remain secret. The algorithm uses key generation method by random number in algorithm for increasing efficiency of algorithm. The algorithm use key size of 512 bits for p...

The defense of computer systems from malicious software attacks, such as viruses and worms, is a key aspect of computer security. The analogy between malicious software and biological infections suggested us to use the κcalculus, a formalism originally developed for the analysis of biological systems, for the formalization and analysis of malicious software. By modeling the different actors inv...

Secure sensor localization is a prerequisite for many sensor networks to retrieve trustworthy data. However, most of existing node positioning systems were studied in trust environment and are therefore vulnerable to malicious attacks. In this work, we develop a robust node positioning mechanism(ROPM) to protect localization techniques from position attacks. Instead of introducing countermeasur...

Gossip-based protocols are an e cient mechanism for man-aging pure unstructured peer-to-peer (P2P) networks. Such protocols are Newscast, Cyclone, Lbpcast, etc. They have overcome from several di culties of such P2P random overlay connection. Such difficulties are randomness, high churn rate, very large unstructured distributed net-work, etc. But the performance of all gossip-based protocols ha...

With the rising number of cyber threats in communication networks, there is a demand for attack analysis and the identification of new threats. Honeypots, tools for attack analysis and zero-day exploit discovery, are passive in waiting for an attacker. This paper proposes a novel approach to the effective utilization of honeypots based on cooperation between honeypots and the network in which t...

Featured with anonymity and spontaneity, ring signature has been widely adopted in various environments to offer anonymous authentication. To simplify the certificate management in traditional public key infrastructure (PKI) and solve the inherent key escrow problem in the Identity-based cryptography, Qin et al. propose a pairingfree ring signature scheme in the certificate-based cryptosystem r...

Noisy channels are a powerful resource for cryptography as they can be used to obtain information-theoretically secure key agreement, commitment and oblivious transfer protocols, among others. Oblivious transfer (OT) is a fundamental primitive since it is complete for secure multiparty computation, and the OT capacity characterizes how efficiently a channel can be used for obtaining string obli...

The threat of malicious insiders to organizations is persistent and increasing. We examine 15 real cases of insider threat sabotage of IT systems to identify several key points in the attack time-line, such as when the insider clearly became disgruntled, began attack preparations, and carried out the attack. We also determine when the attack stopped, when it was detected, and when action was ta...