A Survey of Research Progress and Development Tendency of Attribute-Based Encryption

With the development of cryptography, the attribute-based encryption (ABE) draws widespread attention of the researchers in recent years. The ABE scheme, which belongs to the public key encryption mechanism, takes attributes as public key and associates them with the ciphertext or the user’s secret key. It is an efficient way to solve open problems in access control scenarios, for example, how to provide data confidentiality and expressive access control at the same time. In this paper, we survey the basic ABE scheme and its two variants: the key-policy ABE (KP-ABE) scheme and the ciphertext-policy ABE (CP-ABE) scheme. We also pay attention to other researches relating to the ABE schemes, including multiauthority, user/attribute revocation, accountability, and proxy reencryption, with an extensive comparison of their functionality and performance. Finally, possible future works and some conclusions are pointed out

Protocols for Secure Computation on Privately Encrypted Data in the Cloud

Cloud services provide clients with highly scalable network, storage, and computational resources. However, these service come with the challenge of guaranteeing the confidentiality of the data stored on the cloud. Rather than attempting to prevent adversaries from compromising the cloud server, we aim in this thesis to provide data confidentiality and secure computations in the cloud, while preserving the privacy of the participants and assuming the existence of a passive adversary able to access all data stored in the cloud. To achieve this, we propose several protocols for secure and privacy-preserving data storage in the cloud. We further show their applicability and scalability through their implementations. we first propose a protocol that would allow emergency providers access to privately encrypted data in the cloud, in the case of an emergency, such as medical records. Second, we propose various protocols to allow a querying entity to securely query privately encrypted data in the cloud while preserving the privacy of the data owners and the querying entity. We also present cryptographic and non-cryptographic protocols for secure private function evaluation in order to extend the functions applicable in the protocols