Spring 2001cs444n37 Key archival service Maintains timed history of signature verification keys –Most notably the master verification keys used and published by CAs Accumulates key updates and revocation information At end of round key archive is modified and time stamped to reflect changes –Use hash trees to represent time stampable snapshots of CA –Uses authenticated search trees for accountability [Buldas et al., 2000] Snapshot roots archived in a Time Tree –Also an authenticated search tree –Ordered by time
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