Abstract
Cloud-based big data frameworks help collaborative healthcare service providers to efficiently store and manage large-scale health data. In such frameworks each cloud data source is autonomous and exchanges data with another cloud using pair-wise communication for user queries by creating an on-the-fly data-exchange session. The frameworks provide a platform for sharing or exchanging health data residing in multiple clouds for the purpose of data analysis, decision making, and improving patients' treatment. As healthcare data are extremely sensitive, security is vital when sharing such data in a collaborative framework. Since clouds may exchange sensitive patient health data over an insecure channel, the sensitive data might be accessed or intercepted by malicious users or intruders. In this circumstance, a central third-party security mechanism (e.g., Public Key Infrastructure) can not protect confidential data. Concerning pair-wise, on-the-fly data exchange, this paper presents a two-phase security protocol that uses pairing-based cryptography. Each cloud computes a secret session key dynamically by computing a pairing in an elliptic curve. Validating the presented protocol, a formal verification proves that the proposed protocol is robust and safe against the masquerade, man-in-the-middle, and replay attacks.