Contributory Broadcast Encryption With Efficient Encryption And Short CipherText - Coimbatore

ABSTRACT
Traditional broadcast encryption (BE) schemes allow a sender to securely broadcast to any subset of members but require a trusted party to distribute decryption keys. Group key agreement (GKA) protocols enable a group of members to negotiate a common encryption key via open networks so that only the group members can decrypt the cipher texts encrypted under the shared encryption key, but a sender cannot exclude any particular member from decrypting the cipher texts. In this paper, we bridge these two notions with a hybrid primitive referred to as contributory broadcast encryption (ConBE). In this new primitive, a group of members negotiate a common public encryption key while each member holds a decryption key. A sender seeing the public group encryption key can limit the decryption to a subset of members of his choice. Following this model, we propose a ConBE scheme with short ciphertexts. The scheme is proven to be fully collusion-resistant under the decision n-Bilinear Diffie-Hellman Exponentiation (BDHE) assumption in the standard model. Of independent interest, we present a new BE scheme that is aggregatable. The aggregatability property is shown to be useful to construct advanced protocols.

For more details, Contact
ph:9095395333,9159115969

Office Address:
LansA Informatics Pvt Ltd,
165, 5th Street, Cross cut road,
Gandhipuram, Coimbatore-641012