International Business Machines Corporation

Nokia Corporation

Rafik Chaabouni

Jan Leonhard Camenisch

Imad Aad

Serge Vaudenay

Abhi A Shelat

Pentti Valtteri Niemi

Atefeh Mashatan

A method for providing efficient management of certificate revocation may comprise storing a list of identifiers of digital certificates including a revocation list defining a list of revoked certificates in an accumulator, storing a witness value in association with at least some entries in the revocation list in which the witness value provides proof of the membership or non-membership of an identifier in the revocation list, enabling generation of a new accumulator and a new witness value responsive to each insertion or deletion of an entry in the revocation list, and enabling batch updates to the revocation list using a reduced bitlength value generated based on to a ratio of a value generated based on elements added to the revocation list to a value generated based on elements deleted from the revocation list. A corresponding apparatus is also provided. A method for certificate authorities (CA) that use Bloom filters for certificate revocation list (CRL) compression that enables the CA to hash only the entry that is to be un-revoked so that a good compression rate may be provided while avoiding computation of the entire CRL for each un-revocation.

Method and apparatus for providing efficient management of certificate revocation

A method and apparatus for proving and a method and apparatus for verifying that a secret value is a member of a predetermined set of values. The proving mechanism receives a set of signatures which has respective values in the predetermined set signed using a private key. The proving mechanism sends to the verifying mechanism a commitment on the secret value of the proving mechanism. The proving mechanism and verifying mechanism then communicate to implement a proof of knowledge protocol demonstrating knowledge by the proving mechanism of a signature on the secret value committed to in the commitment, thus proving that the secret value is a member of the predetermined set.

Set membership proofs in data processing systems

Growing community of inventors

Vésenaz, Switzerland

Rafik Chaabouni