Biblio

Audit logs are widely used in information systems nowadays. In cloud computing and cloud storage environment, audit logs are required to be encrypted and outsourced on remote servers to protect the confidentiality of data and the privacy of users. The searchable encrypted audit logs support a search on the encrypted audit logs. In this paper, we propose a privacy-preserving and unforgeable searchable encrypted audit log scheme based on PEKS. Only the trusted data owner can generate encrypted audit logs containing access permissions for users. The semi-honest server verifies the audit logs in a searchable encryption way before granting the operation rights to users and storing the audit logs. The data owner can perform a fine-grained conjunctive query on the stored audit logs, and accept only the valid audit logs. The scheme is immune to the collusion tamper or fabrication conducted by server and user. Concrete implementations of the scheme is put forward in detail. The correct of the scheme is proved, and the security properties, such as privacy-preserving, searchability, verifiability and unforgeability are analyzed. Further evaluation of computation load shows that the design is of considerable efficiency.

Aiming to reduce the cost and complexity of maintaining networking infrastructures, organizations are increasingly outsourcing their network functions (e.g., firewalls, traffic shapers and intrusion detection systems) to the cloud, and a number of industrial players have started to offer network function virtualization (NFV)-based solutions. Alas, outsourcing network functions in its current setting implies that sensitive network policies, such as firewall rules, are revealed to the cloud provider. In this paper, we investigate the use of cryptographic primitives for processing outsourced network functions, so that the provider does not learn any sensitive information. More specifically, we present a cryptographic treatment of privacy-preserving outsourcing of network functions, introducing security definitions as well as an abstract model of generic network functions, and then propose a few instantiations using partial homomorphic encryption and public-key encryption with keyword search. We include a proof-of-concept implementation of our constructions and show that network functions can be privately processed by an untrusted cloud provider in a few milliseconds.