SPPS: Secure Policy-based Publish/Subscribe System for V2C Communication

The Publish/Subscribe (Pub/Sub) pattern is an attractive paradigm for supporting Vehicle to Cloud (V2C) communication. However, the security threats on confidentiality, integrity, and access control of the published data challenge the adoption of the Pub/Sub model. To address that, our paper proposes a secure policy-based Pub/Sub model for V2C communication, which allows to encrypt and control the access to messages published by vehicles. A vehicle encrypts messages with a symmetric key while saving the key in distributed shares on semi-honest services, called KeyStores, using the concept of secret sharing. The security policy, generated by the same vehicle, authorizes certain cloud services to obtain the shares from the KeyStores. Here, granting access rights takes place without violating the decoupling requirement of the Pub/Sub model. Experimental results show that, besides the end-to-end security protection, our proposed system introduces significantly less overhead (almost 70% less) than the state-of-the-art approach SSL when reestablishing connections, which is a common scenario in the V2C context due to unreliable network connection.