Certificateless searchable public key authenticated encryption with designated tester for cloud-assisted medical Internet of Things

In the past few years, internet of things has been explored in medical area to achieve high efficiency and accuracy in the medical treatment and management. One of the most powerful technologies called the medical Internet of Things (mIoT), is underpinned by the considerable computational ability of cloud and the efficient data collection of medical sensors. As the data is transmitted over open network, security remains a paramount concern in mIoT. Encryption techniques may help to protect patient privacy, but they limit the future retrieval of the encrypted data. To uplift this limitation, public key encryption with keyword search (PEKS) has been introduced. However, most of the existing PEKS schemes are based on public key infrastructure or identity-based cryptography, which suffers from the certificate management issue and key escrow problem in system deployment, respectively. Moreover, inside keyword guessing attack seems to become a severe issue to violate privacy in data search. To address these issues, we present a certificateless searchable public key authenticated encryption scheme with designated tester (CL-dPAEKS), which, we believe, is suitable for cloud-assisted mIoT. We prove that our scheme can resist various types of attacks, and it is more secure than other schemes that built on certificateless cryptography, without significant loss in efficiency.