Summary: The extended abstract of this work appears in D. Naccache, editor, Topics in Cryptology
CT-RSA 2001, Volume 2020 of Lectures Notes in Computer Science, San Francisco, CA, USA,
Apr. 812, 2001. Springer-Verlag, Berlin, Germany. This is the full version.
Forward-Secure Threshold Signature Schemes
Michel Abdalla Sara Miner Chanathip Namprempre
Department of Computer Science & Engineering
University of California at San Diego
9500 Gilman Drive
La Jolla, California 92093, USA
We construct forward-secure threshold signature schemes. These schemes have the follow-
ing property: even if more than the threshold number of players are compromised, it is not
possible to forge signatures relating to the past. This property is achieved while keeping the
public key fixed and updating the secret keys at regular intervals. The schemes are reason-
ably efficient in that the amount of secure storage, the signature size and the key lengths do
not vary proportionally to the number of time periods during the lifetime of the public key.
Both proposed schemes are based on the Bellare-Miner forward-secure signature scheme.
One scheme uses multiplicative secret sharing and tolerates mobile eavesdropping adver-