Access Restriction

Author Chan, Aldar C. -F.
Source CiteSeerX
Content type Text
File Format PDF
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Trusted Time Server ♦ Self-authenticated Time-bound Key Update ♦ Precise Absolute Release Time Specification ♦ Time-lock Puzzle Approach ♦ Partial Order Planning ♦ Server-based Scheme ♦ Timed Release Cryptography ♦ Bilinear Pairing ♦ Gap Diffie-hellman Group ♦ Relative Time Problem ♦ Single Form ♦ Coarse-grained Release Time ♦ Key Insulation ♦ Xuanlong Nguyen ♦ Subbarao Kambhampati ♦ General Policy Lock Mechanism ♦ Serverbased Approach ♦ Desirable Property
Description 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 (serverbased 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. 1.
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Learning Resource Type Article
Publisher Date 2005-01-01
Publisher Institution In Proc. IJCAI '01