Collusion Defender: Preserving Subscribers’ Privacy In Publish And Subscribe Systems

Collusion Defender: Preserving Subscribers’ Privacy In Publish and Subscribe Systems

ABSTRACT

Publish and subscribe (pub/sub) systems enable dissemination of data from publishers to interested subscribers in a loosely-coupled manner, where the data is transmitted without establishing direct contacts between publishers and subscribers. Despite its benefits, pub/sub systems present several security and privacy challenges as the data is routed through a set of brokers in multi-party distributed system. With the proliferation of outsourced systems, pub/sub services are typically based on third party servers (e.g., cloud servers). Unfortunately, these servers can be compromised or hacked. For instance, in 2016, an attack on the Yahoo platform led to the leakage of 1 billion user accounts. A viable mechanism to protect sensitive publications and subscriptions is to encrypt the data before it is disseminated through the brokers. State-of-the-art approaches allow brokers to perform encrypted matching without revealing publications and subscriptions. However, if malicious brokers collude with malicious subscribers or publishers, they can learn the interests of innocent subscribers, even when the interests are encrypted. Privacy-preserving pub/sub system that protects subscriptions effectively and resists collusion attacks using a multi-broker setting without compromising the loosely-coupled property of the pub/sub model.A pub/sub system that ensures confidentiality of publications and subscriptions in the presence of un-trusted brokers.