any heavy computations like pairing, multiplication on elliptic curves and is very efficient. To the best of our knowledge there exists three online/offline signcryption schemes in the literature: we propose various attacks on all the existing schemes. Then, we give the first efficient and provably

Abstract – A secure channel between a sensor node and internet host is created, hence new security challenges arises and wireless sensor networks is integrated into internet of things. We use heterogeneous online/offline signcryption scheme so that secure communication is provided. We use bilinear

such as pairings or multiplications on elliptic curve. It is particularly suitable for power-constrained devices such as smart cards. We give a concrete implementation of online/offline identity-based signcryption, which is very efficient and flexible. Unlike all the previous schemes in the literature, our scheme

signature by a quadratic factor. In this paper we use the recently introduced notion of a trapdoor hash function to develop a new paradigm called hash-sign-switch, which can convert any signature scheme into a highly efficient on-line/off-line signature scheme: In its recommended implementation, the on-line

A signcryption scheme allows a sender to produce a ciphertext for a receiver so that both confidentiality and non-repudiation can be ensured. It is built to be more efficient and secure, for example, supporting insider security, when compared with the conventional sign-then-encrypt approach

A generic construction of identity-based online/ offline signcryption

Nowadays, scientific research has brought challenging calculations to solve intractable problems for a single machine. Desktop Grids has appeared as an interesting and cheap solution to perform such computations. Desktop Grids profits of machine idle times in a network to, altogether, perform a hard computation. On the Internet, where only 5 to 10 % of the computational power of personal computers is used, platforms like BOINC [1] or SETI@home [2] uses volunteers machines to perform hard computations in mathematics, biology, medicine or to search for intelligent life outside earth in case of

Abstract In this paper, we present an on-line electronic payment system for low-value transaction. We use the concept of signcryption for each communication between any pair of entities and offers token updation instantly as an add-on feature to existing on-line e-cash systems where token

encryption scheme proposed in ACNS 09 by Liu et al. [7]. The scheme in [7] is the first identity based online offline encryption scheme in the random oracle model, in which the message and recipient are not known during the offline phase. We show that this scheme is not CCA secure. We show the weakness

are more efficient than DSS and admit provable security in the model of Pointcheval and Stern. • This is followed by Part II where two signcryption schemes are described. A major advantage of signcryption schemes is that they fulfill both the functions of digital signature and public key encryption in a