e-SAFE: A secure and efficient access control scheme with attribute convergence and user revocation in fog enhanced IoT for E-Health

The growth of IoT led to a surge in connected devices and data production in the medical field. Therefore, to meet the rising demand for modern healthcare services, Fog and Cloud services come as a rescue for IoT-based equipment. As data travels through several levels, providing security to such data is challenging. The CP-ABE cryptographic approach allows for efficient access control. However, none of the known cryptographic CP-ABE approaches that provide granular access control offers the following features: attribute convergence, privileged access, user revocation, and outsourcing capabilities altogether. Thus, we present e-SAFE, a CP-ABE approach which addresses all these issues. In addition, in e-SAFE, the data users with resource-constrained medical gadgets must save just a constant and small-size decryption key on their gadgets. According to our assessment of security and performance, e-SAFE is found to be a secure and efficient access control technique for IoT gadgets.