[Resource Topic] 2003/095: Public Key Trace and Revoke Scheme Secure against Adaptive Chosen Ciphertext Attack

Welcome to the resource topic for 2003/095

Public Key Trace and Revoke Scheme Secure against Adaptive Chosen Ciphertext Attack

Authors: Yevgeniy Dodis, Nelly Fazio


A (public key) Trace and Revoke Scheme combines the functionality
of broadcast encryption with the capability of traitor tracing.
Specifically, (1) a trusted center publishes a single public key
and distributes individual secret keys to the users of the system;
(2) anybody can encrypt a message so that all but a specified
subset of revoked'' users can decrypt the resulting ciphertext; and (3) if a (small) group of users combine their secret keys to produce a pirate decoder’‘, the center can trace at least one of
the ``traitors’’ given access to this decoder.

We construct the first chosen ciphertext (CCA2) secure Trace and
Revoke Scheme based on the DDH assumption. Our scheme is also the
first adaptively secure scheme, allowing the adversary to corrupt
players at any point during execution, while prior works (e.g.,
[NP00,TT01]) only achieves a very weak form of non-adaptive
security even against chosen plaintext attacks. In fact, no CCA2
scheme was known even in the symmetric setting.

Of independent interest, we present a slightly simpler
construction that shows a ``natural separation’’ between the
classical notion of CCA2 security and the recently proposed
[Sho01,ADR02] relaxed notion of gCCA2 security.

ePrint: https://eprint.iacr.org/2003/095

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .