Traditionally, a ciphertext from an identity-based broadcast encryption can be distributed to a group of receivers whose identities are included in the ciphertext. Once the ciphertext has been created, it is not possible to remove any intended receivers from it without conducting decryption. In this paper, we consider an interesting question: how to remove target designated receivers from a cip...

We provide algorithms to solve the free riders problem in broadcast encryption. In this problem, the broadcast server is allowed to choose some small subset F of the revoked set R of users to allow to decrypt the broadcast, despite having been revoked. This may allow the server to significantly reduce network traffic while only allowing a small set of non-privileged users to decrypt the broadca...

Traditional broadcast encryption (BE) schemes al-low 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 ciphertexts encrypted under the shared encryption key, but a send...

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 ciphertexts encrypted under the shared encryption key, but a sende...

Broadcast encryption (BE) schemes allow a sender to securely broadcast to any subset of members but requires 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 members can decrypt the ciphertexts encrypted under the shared encryption key, but a sender cannot exclude ...

Information dissemination in vehicular ad hoc networks (VANETs) is inseparable from the interaction between vehicles and infrastructure. The trust authority (TA) often plays a pivotal role VANETs requires with multiple vehicles. However, when TA sends same message to vehicles, there are many redundancies, as it needs negotiate each vehicle send them different ciphertexts. This greatly reduces w...

Data stored in cloud storage sometimes requires long-term security due to its sensitivity (e.g.,genome data), and therefore, it also requires flexible access control for handling entities who canuse the data. Broadcast encryption can partially provide such flexibility by specifying privilegedreceivers so that only they can decrypt a ciphertext. However, once privileged receivers...