In this paper, the authors address privacy and malicious behavior for e-health, since they argue that it is particularly ideal for use in smart cities. The authors’ concern for users is privacy protection through cryptographic encryption. The premise is that smart city urbanization is moving to the cloud and both privacy and maliciousness are of paramount concern.

They argue that attribute-based encryption has more secure advantages over other systems, in particular in tracing a malicious user. In order to accomplish a secure e-health system, both user traceability and authority accountability are added to attribute-based encryption.

The authors’ contribution is a secure smart health system that provides users with smart health records for securely sharing their data with authorized users. There are three specific proposals: the system architecture model of a secure smart health system, a way to trace malicious user behaviors, and a security scheme that is secure in a random oracle model against adaptive adversaries.

The authors also provide a performance analysis match against alternatives, which proves their system is more secure than previous methods. Their “secure smart health system simultaneously supports user traceability, authority accountability, and auditing in [their proposed] white box model.” The proposal is efficient and practical for a smart city environment.