Threshold secret sharing schemes are used to divide a given secret by a dealer in parts such that no less than the threshold number of shareholders can reconstruct the secret. However, these schemes are susceptible to the malicious behavior of a shareholder or a dealer. To prevent such attacks, it is necessary to make a provision for verification of the integrity of the shares distributed by th...

This paper investigates the security of Proactive Secret Sharing Schemes. We first consider the approach of using commitment to 0 in the renewal phase in order to refresh the player’s shares and we present two types of attacks in the information theoretic case. Then we prove the conditions for the security of such a proactive scheme. Proactivity can be added also using re-sharing instead of com...

We propose a tracing scheme of e-cash which has not only fair tracing ability but also lower computational complexity for comparisons. Many other protocols allow optimistic fair tracing which means that illegal tracing can be found after tracing and depositing in bank. But in this scheme, illegal tracing done by bank alone is impossible. We propose a marking mechanism based on a variant of an O...

Voice communication carried out using the Internet Protocol (IP) for the transaction is known as Voice over Internet Protocol (VoIP). Voice over Internet Protocol is a technology for communicating using “Internet protocol” instead of traditional analog systems. Some VoIP services need only a regular phone connection, while others allows making telephone calls using an Internet connection instea...

Terrorist fraud is a class of relay attacks against distancebounding (DB) protocols in which a distant malicious prover colludes with an attacker located in a verifier’s proximity when authenticating. Existing DB protocols resisting such attacks are designed to be lightweight and thus symmetric, relying on a secret shared by the prover and the verifier. Recently, several asymmetric distance-bou...

In this article, the authors propose an approach for privacy preserving distributed clustering that assumes malicious model. In the literature, there do exist, numerous approaches that assume a semi honest model. However, such an assumption is, at best, reasonable in experimentations; rarely true in real world. Hence, it is essential to investigate approaches for privacy preservation using a ma...

Verifiable secret sharing schemes are important in cloud computing environments. Thus a key can be distributed over many servers by threshold secret sharing mechanism. The key is then reconstructed when needed. Secret sharing has also been suggested for sensor networks where the links are liable to be tapped by sending the data in shares which makes the task of the eavesdropper harder. The secu...