LORENA: Low memORy symmEtric-Key geNerAtion Method for Based on Group Cryptography Protocol Applied to the Internet of Healthcare Things

The advent of the Internet of Things (IoT) has revolutionized the way we, as a society, perform different daily tasks, such as healthcare. The Internet of Health Things (IoHT) is an example of the IoT specialization handling sensitive user data and applications requiring solutions to address different security and privacy issues. IoHT requires security mechanisms in communication. However, these mechanisms need to consider the limitations of the IoHT devices and communication. Hence, symmetric cryptography is suitable to IoHT once it uses less computational and communication resources than asymmetric cryptography. But, symmetric cryptography relies on the agreement of the cryptography material (e.g., the cryptography key) among the devices, a challenge in networks with resource constraints, such as IoHT. Therefore, this article presents a Low memORy symmEtric-key geNerAtion (LORENA) method based on group secret key agreement protocol for IoHT environments. Evaluations have focused on computational efficiency, data security requirements, and scalability in a network with up to ten devices per group using a simulator and a device with limited computational resources. Results show that the protocol is lightweight, secure, and feasible to IoHT networks, presenting a linear growth in the 128-bit key distribution time for each device entering the group.