Broadcast encryption (BE) is a very helpful protocol to forward a message to a group of users proficiently. Identity based broadcast encryption (IBBE) use identities of users as public key. As it is one to many encryption, the decryption generally needs high computation cost. Edge computing reduces the computation cost. Edge server do most of the computations. The final computation is carried out by receiver. This is very efficient to use for the devices that has low computation power (like-IoT device, mobile etc). In IBBE, there is a key generation centre who generates secret key for each identity. Hence, it is suited for decrypting the ciphertext. To decode this, Zhao et al. offered the notion of accountable authority broadcast encryption scheme where secret key will be kept secure to user (IoT device) only. Their scheme uses random oracles to proof the security. This paper presents a public traceable weak-black-box accountable authority identity-based broadcast encryption with outsourced partial decryption (A-IBBEOPD) scheme. We are able to construct accountable authority broadcast encryption supporting edge computing and proved the security using some mathematical hardness problem without using the random oracles. It also supports public traceability. Furthermore, our construction has a constant-size ciphertext, secret key. We use edge servers without leaking messages and secret keys to minimize the time of computation in time of decryption. We have implemented our construction and showed that end devices (like IoT devices) use edge computing and efficiently reduce the decryption time.
Acharya et al. (Fri,) studied this question.