Informatica

Since threshold proxy signature has been proposed, all threshold proxy signature schemes are based on the discrete logarithm problems in the modular multiplicative group which has an element g with a large prime order. Nowadays this kind of threshold proxy signature schemes become more and more complex and time-consuming for security and specific requirement. In this paper, we propose a (bilinear) pairing-based threshold proxy signature scheme with known signers, analyze its security and check the following properties the proposed scheme has: non-repudiation, unforgeability, identifiability, distinguishability, verifiability, prevention of misuse of proxy signing right, etc. Moreover, we point out that the proposed scheme is of great efficiency by comparing it with Sun’s and Hsu et al.’s scheme.

Verifiable encryption is a primitive that can be used to build extremely efficient fair exchange protocols where the items exchanged represent digital signatures. Such protocols may be used to digitally sign contracts on the Internet. This paper presents an efficient protocol for verifiable encryption of digital signatures that improves the security and efficiency of the verifiable encryption scheme of Ateniese. Our protocol can be applied to group signatures, key escrow and publicly verifiable secret and signature sharing to prove the fairness.

Technological advances have allowed all conferees to hold a mobile conference via wireless communication. When designing a conference scheme for mobile communications it should be taken into account that the mobile users are typically using portable devices with limited computing capability. Moreover, wireless communications are more susceptible to eavesdropping and unauthorized access than conversations via wires. Based on elliptic curve cryptography, this article proposes a secure mobile conference scheme which allows a participant to join or quit a teleconference dynamically. Without any interactive protocol among participants are required to construct the common key. This can save on communication overhead.

Wireless communication techniques provide convenience for users to get desired information. Construction and management costs of information provision systems with low computational-ability devices, such as RFID devices, are low so lightweight authentication protocols are required for information security. In this paper, two lightweight authentication protocols are proposed for reliable information provision systems with low computational-ability devices. The first protocol is for public information, and the other ensures that only authorized users can get information.

Amidst the debate on the relative merits of push versus pull technologies, the role of information dynamics over the Internet in shaping truly compelling use of the medium for electronic commerce is being recognized. Focused Broadcasting, a business model of matching classified and want ads using the World Wide Web, is positioned as an example of a balanced approach whose success may be predictable based on market research and analysis. This article reports on a study conducted in New Zealand of Internet user attitudes toward this type of service.