DocumentCode :
3294642
Title :
Scalable, Server-Passive, User-Anonymous Timed Release Cryptography
Author :
Chan, Aldar C F ; Blake, Ian F.
Author_Institution :
Toronto Univ., Ont.
fYear :
2005
fDate :
10-10 June 2005
Firstpage :
504
Lastpage :
513
Abstract :
We consider the problem of sending messages into the future, commonly known as timed release cryptography. Existing schemes for this task either solve the relative time problem with uncontrollable, coarse-grained release time (time-lock puzzle approach) or do not provide anonymity to senders and/or receivers and are not scalable (server-based approach). Using a bilinear pairing on any Gap Diffie-Hellman group, we solve this problem by giving scalable, server-passive and user-anonymous timed release public-key encryption schemes allowing precise absolute release time specifications. Unlike the existing server-based schemes, the trusted time server in our scheme is completely passive - no interaction between it and the sender or receiver is needed; it is even not aware of the existence of a user, thus assuring the privacy of a message and the anonymity of both its sender and receiver. Besides, our scheme also has a number of desirable properties including a single form of update for all users, self-authenticated time-bound key updates, and key insulation, making it a scalable and appealing solution. It could also be easily generalized to a more general policy lock mechanism
Keywords :
computer networks; data communication; public key cryptography; Gap Diffie-Hellman group; bilinear pairing; coarse-grained release time; key insulation; policy lock; public-key encryption; relative time problem; scalable timed release cryptography; self-authenticated key updates; server-based approach; server-based schemes; server-passive timed release cryptography; time server; time-bound key updates; time-lock puzzle; uncontrollable release time; user-anonymous timed release cryptography; Atomic clocks; Cryptography; Delay; Distributed computing; Global Positioning System; Government; Insulation; Privacy; Public key; Seals;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Distributed Computing Systems, 2005. ICDCS 2005. Proceedings. 25th IEEE International Conference on
Conference_Location :
Columbus, OH
ISSN :
1063-6927
Print_ISBN :
0-7695-2331-5
Type :
conf
DOI :
10.1109/ICDCS.2005.72
Filename :
1437112
Link To Document :
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