Modern technologies of mobile computing and wireless sensing prompt the concept of pervasive social network (PSN)-based healthcare. To realize the concept, the core problem is how a PSN node can securely share health data with other nodes in the network. In this paper, we propose a secure system for PSN-based healthcare. Two protocols are designed for the system. The first one is an improved version of the IEEE 802.15.6 display authenticated association. It establishes secure links with unbalanced computational requirements for mobile devices and resource-limited sensor nodes. The second protocol uses blockchain technique to share health data among PSN nodes. We realize a protocol suite to study protocol runtime and other factors. In addition, human body channels are proposed for PSN nodes in some use cases. The proposed system illustrates a potential method of using blockchain for PSN-based applications.

Smart Grid is an indispensable part of the Internet of Things (IoT) and has the potential to revolutionise the electricity energy industry. Smart meters, as an important component of Smart Grid, are responsible for the exchange of information between end consumers and service providers. Smart meters and service providers need to use authentication key exchange protocols (AKE) to establish a secure session for secure information transmission. However, The current state-of-the-art lightweight solutions do not support identity anonymity and mostly have high communication costs. This paper proposes a lightweight and secure mutual authentication scheme, which is particularly designed for devices with limited computing capability to provide identity anonymity such as smart meters, based on the Shangyong Mima 2 (SM2) AKE protocol stipulated by the State Cryptography Administration of China. We conducted formal analysis of the security of the proposed scheme and proved its security. In addition, the computational overhead of the protocol was evaluated through performance analysis. Compared with related lightweight protocols, our scheme can reduce up to 30%-40% computational overhead. The results verified that the proposed scheme is indeed suitable for secure communication involving devices with constrained computing capability.

Storage is a promising application for permission-less blockchains. Before blockchain, cloud storage was hosted by a trusted service provider. The centralized system controls the permission of the data access. In web3, users own their data. Data must be encrypted in a permission-less decentralized storage network, and the permission control should be pure cryptographic. Proxy re-encryption (PRE) is ideal for cryptographic access control, which allows a proxy to transfer Alice’s ciphertext to Bob with Alice’s authorization. The encrypted data are stored in several copies for redundancy in a permission-less decentralized storage network. The redundancy suffers from the outsourcing attack. The malicious resource provider may fetch the content from others and respond to the verifiers. This harms data integrity security. Thus, proof-of-replication (PoRep) must be applied to convince the user that the storage provider is using dedicated storage. PoRep is an expensive operation that encodes the original content into a replication. Existing PRE schemes cannot satisfy PoRep, as the cryptographic permission granting generates an extra ciphertext. A new ciphertext would result in several expensive replication operations. We searched most of the PRE schemes for the combination of the cryptographic methods to avoid transforming the ciphertext. Therefore, we propose a new PRE scheme. The proposed scheme does not require the proxy to transfer the ciphertext into a new one. It reduces the computation and operation time when allowing a new user to access a file. Furthermore, the PRE scheme is CCA (chosen-ciphertext attack) security and only needs one key pair.

Edge Artificial Intelligence (AI) is a timely complement of cloud-based AI. By introducing intelligence to the edge, it alleviates privacy concerns of streaming and storing data to the cloud, enables real-time operations where milliseconds matter, and brings AI services to remote areas with poor networking infrastructures. Security is a significant problem in Edge AI applications such as self-driving cars and intelligent healthcare. Since the edge devices are empowered to process data and take actions, attacking and compromising them can cause serious damage. However, the wide deployment of computationally limited devices in edge environments and the increasing happening of side-channel (or leakage) attacks pose critical challenges to security. This paper thereby aims to enhance the security for Edge AI by designing and developing lightweight and leakage-resilient authenticated key exchange (LRAKE) protocols. Compared with available LRAKE protocols, the proposed protocols in this paper can be effortless applied in some mainstreaming security and communication standards. Moreover, this paper realizes prototypes and presents implementation details; and a use case of applying the proposed protocol in Bluetooth 5.0 is illustrated. The theoretical design and implementation details will provide a guidance of applying the LRAKE protocols in Edge AI applications.

Wireless updating is an essential method to update system files or fix bugs in Internet of Things (IoT) devices. A significant and challenging problem in wireless updating is security. First, without security guarantees, attackers can utilize the updating procedure to install harmful programs into the victim devices. Second, it is challenging to provide security for wireless updating, since in many IoT scenarios, the devices to be updated are computationally limited devices and located far from the center that issues update files. Currently, there are two types of solution to protect the wireless updating. The first one is the transport layer security (TLS) protocol or secure sockets layer (SSL) protocol that are used by wireless updating schemes for mobile terminals with the following operation systems: Windows, Debian, Android, and iOS. Another solution is the elliptic curve Diffie-Hellman (ECDH)-based handshake in the software-defined function (SDF) wireless updating scheme for the IoT devices. However, both the two solutions require equal computation tasks on the update file issuing center and the device to be updated. Normally, the former is much powerful than the latter. Therefore, to further address the security problem in wireless updating, we propose a novel solution with unbalanced computation costs on the two parties. In particular, we design an improved ECDH-based handshake protocol for the SDF wireless updating scheme, namely, the unbalanced OpenFunction handshake protocol. The protocol transfers significant computation task from the limited IoT device to the powerful center. The security of the protocol is analyzed. A prototype is realized to test the performance of the protocol. The experiment results show that in the same experimental platform, our protocol is much lightweight than the TLS handshake protocol and SSL handshake protocol.