Online/offline identity-based signcryption revisited

Joseph K Liu, Joonsang Baek, Jianying Zhou

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

22 Citations (Scopus)


In this paper, we redefine a cryptographic notion called Online/Offline Identity-Based Signcryption. It is an online/offline version of identity-based signcryption, where most of the computations are carried out offline while the online part does not require any heavy computations 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 does not require the knowledge of receiver s information (either public key or identity) in the offline stage. The receiver s identity and the message to be signcrypted are only needed in the online stage. This feature provides a great flexibility to our scheme and makes it practical to use in real-world applications. To our knowledge, our scheme is the first one in the literature to provide this kind of feature. We prove that the proposed scheme meets strong security requirements in the random oracle model, assuming the Strong Diffie-Hellman (SDH) and Bilinear Diffie-Hellman Inversion (BDHI) are computationally hard.
Original languageEnglish
Title of host publicationProceedings of the 6th International Conference on Information Security and Cryptology (Inscrypt 2010)
EditorsXuejia Lai, Moti Yung, Dongdai Lin
Place of PublicationHeidelberg Germany
Pages36 - 51
Number of pages16
ISBN (Print)978-364221517-9
Publication statusPublished - 2010
Externally publishedYes
EventInternational Conference on Information Security and Cryptology (Inscript) 2010 - Shanghai China, Shanghai, China
Duration: 20 Oct 201024 Oct 2010
Conference number: 6th


ConferenceInternational Conference on Information Security and Cryptology (Inscript) 2010
Abbreviated titleInscrypt 2010
OtherThe 6th China International Conference on Information Security and Cryptology (Inscrypt 2010)
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