International Association for Cryptologic Research

International Association
for Cryptologic Research


Yanjiang Yang


Efficient Online/Offline Identity-Based Signature for Wireless Sensor Network
In this paper, we present an \emph{online/offline identity-based signature} scheme for the wireless sensor network (WSN). We argue that due to significant reduction in computational and storage costs, our scheme is particularly suitable for the WSN environment with severely constrained resources. One of the interesting features of our scheme is that it provides \textit{multi-time} usage of the offline storage, which allows the signer to re-use the offline pre-computed information in polynomial time, in contrast to \textit{one-time} usage in all previous online/offline signature schemes. As evidence of the practicality and feasibility of our scheme to be used in the WSN environment, we provide an actual implementation result of our scheme on the MicaZ platform.
CCA-Secure Unidirectional Proxy Re-Encryption in the Adaptive Corruption Model without Random Oracles
Proxy re-encryption (PRE), introduced by Blaze, Bleumer and Strauss in Eurocrypt'98, allows a semi-trusted proxy to convert a ciphertext originally intended for Alice into an encryption of the same message intended for Bob. PRE has recently drawn great interest, and many interesting PRE schemes have been proposed. However, up to now, it is still an important question to come up with a chosen-ciphertext secure unidirectional PRE in the adaptive corruption model. To address this problem, we propose a new unidirectional PRE scheme, and prove its chosen-ciphertext security in the adaptive corruption model without random oracles. Compared with the best known unidirectional PRE scheme proposed by Libert and Vergnaud in PKC'08, our schemes enjoys the advantages of both higher efficiency and stronger security.