Anonymous, Secure and Robust Multi-Recipient Communication

ABSTRACT

This project proposes models and efficient cryptographic protocols for con- tent distribution that address security and privacy concerns beyond the mere secrecy of the data. Specific goals of the research are to protect the identities of the recipients of the content, and to hide the very fact that communication is taking place. The project includes four main objectives: (1) the design of cryp- tographic constructions for receiver-anonymous broadcast encryption that have performance comparable to standard broadcast encryption; (2) the exploration of the relationship between receiver anonymity and ciphertext ambiguity, which refers to the possibility that a given ciphertext might appear valid to multiple decryptors; (3) the formulation of the concept of broadcast steganography to en- able the use of a broadcast channel as a medium for covert communication; and (4) the investigation of applications such as collaborative cloud storage, whereby a group of users stores and accesses shared content in the cloud privately and obliviously.