Chao Lin

Fujian Normal University · College of Computer and Cyber Security

Privacy-preserving federated learning (PPFL) aims to train a global model for multiple clients while maintaining their data privacy. However, current PPFL protocols exhibit one or more of the following insufficiencies: considerable degradation in accuracy, the requirement for sharing keys, and cooperation during the key generation or decryption pro...

The great economic values of deep neural networks (DNNs) urge AI enterprises to protect their intellectual property (IP) for these models. Recently, proof-of-training (PoT) has been proposed as a promising solution to DNN IP protection, through which AI enterprises can utilize the record of DNN training process as their ownership proof. To prevent...

Cloud storage has been widely used in remote data management, although correct storage of the outsourced file is still challenging in practice. Proofs of Retrievability (PoRs), a storage-oriented cryptographic tool, support integrity checking and efficient retrieval of the file. However, due to the lack of a fully credible oversight mechanism or a...

Vehicular Ad-hoc Networks (VANETs) constitute crucial elements within intelligent transportation systems. However, the rapid development of VANETs has brought forth an increasing number of security concerns. Conditional Privacy-Preserving Certificateless Signature (CPP-CLS) has emerged as a promising solution to ensure data security, preserve vehic...

Threshold anonymous credentials enable users to acquire credentials in a decentralized manner while upholding their privacy. However, distributed network environments, such as electronic voting systems and federated identity management systems, have pressing needs for enhancing security, reducing reliance on fixed-group issuers, and achieving scala...

As a promising technology, key-aggregation searchable encryption with constant computation overhead is especially suitable for sensor nodes with limited computation resources in wireless sensor networks. However, in most of the existing key-aggregation searchable encryption schemes, the authorized aggregation key is generated in a deterministic way...

Electronic Medical Records (EMRs) sharing enhances healthcare and biomedical discoveries but faces challenges: data provider centralization and limited interoperability. Blockchain can address these issues, but existing systems struggle with malicious EMR propagation due to challenges concerning the authenticity, non-repudiation, and integrity of t...

Ethereum leverages ECDSA as the digital signature scheme to validate transactions. From the provable security standpoint, ECDSA built on an 80-bit security Elliptic Curve group can achieve at most 50-bit concrete security, rather than 80-bit security, due to its reduction loss for $2^{30}$ signature queries in security analysis. The state-of-the-...

The Industrial Internet of Things (IIoT) incorporates massive physical devices to collect ambient data. Due to the limited types of equipment in IIoT, most of the data has to be saved on a cloud server before it can be processed and analyzed. The ciphertext generated by traditional encryption techniques is difficult to search in subsequent use. Pub...

Satellite networks, as a recent deployment for technical and economic progress, have shown great advantages to provide diversiform Internet services. However, the networks are grappling with severe congestion caused by a surge in simultaneous requests, which has become more prevalent due to the widespread adoption of satellite constellations. The r...

Federated Learning (FL) enables multiple clients to collaboratively train a model without sharing their private data. However, the deployment of FL in real-world applications is vulnerable to various attacks from both malicious servers and clients. While cryptographic methods are effective in resisting server-side attacks, they undermine the capabi...

Payment Channel Networks (PCNs) are innovative second-layer scaling technologies that aim to improve transaction rates, reduce on-chain storage costs, and enable efficient atomic swaps for blockchain-based cryptocurrencies. Despite offering features like relationship anonymity, scriptless script, and cross-chain fairness, current PCNs encounter cha...

Microgrid is a self-sufficient grid system that covers one or more kinds of distributed energy, where a variety of terminal devices collect, transmit and store electricity data based on fog-based network infrastructure. Due to security and privacy concerns, efficient and secure access control over terminal devices in microgrid is the primary way to...

Image licensing regulates the scope, type, and limitations of using an image through an agreement. However, it is challenging to verify whether an agreement has been fulfilled honestly. Existing techniques, such as watermarking and perceptual hashing, help check image originality and editing operations specified in the agreement, but fail to achiev...

Vehicular Ad-hoc Networks (VANETs) are with great potentials to facilitate traffic management and improve driver safety. Blockchain-based conditional privacy-preserving authentication (BCPPA) is proposed to achieve an optimal tradeoff among anonymity, traceability and key/certificate management in VANETs. Existing BCPPA protocols mitigate these sec...

The rapid development and wide application of blockchain not only highlight the significance of privacy protection (including anonymity and confidentiality) but also the necessity of auditability. While several ingenious schemes such as MiniLedger and traceable Monero supporting both privacy protection and auditability have been proposed, they eith...

Outsourcing computations have been an indispensable part to meet the growing demand of computing capability, among which trust problem is one of critical issues to be solved urgently. Fair payment, as a candidate solution, offers the potential for facilitating fair trading among outsourcing computation participants such as users and workers. Howeve...

Smart grid has been expected to provide exquisite consumption monitoring or energy trading for its equipped abundant facilities together with two-way communication, but it inevitably leads to privacy leakage of consumption data during data retransmission. Although blind signature schemes can reduce the risk of privacy leakage due to the properties...

Credit system is generally associated with the banking and financial institutions, although it has far reaching implications for residents of countries, such as U.S., particularly for those with a poor credit history. Specifically, a credit score computation (CSC) quantifies an individual’s credit value or credit risk, which is used by banking and...

Decentralized Anonymous Credential (DAC) has posed enormous potential in smart grids for protecting user privacy (e.g. preventing user’s daily life from being sketched out). However, the existing DAC protocols still compromise user privacy for a full list of attributes are disclosed during showing credentials. In this paper, to construct a privacy-...

Existing (popular) blockchain architectures, including the widely used Ethereum and Hyperledger, are generally not designed to achieve conflicting properties such as anonymity and regulation, and transparency and confidentiality. In this article, we propose a privacy-preserving permissioned blockchain architecture (PPChain) that permits one to also...

While Vehicular Ad-hoc Networks (VANETs) can potentially improve driver safety and traffic mangement efficiency (e.g. through timely sharing of traffic status among vehicles), security and privacy are two ongoing issues that need to be addressed. Hence, security solutions such as conditional privacy-preserving authentication (CPPA) protocols have b...

The sensing-as-a-service (SaaS) model has been explored to address the challenge of intractability of managing a large number of sensors faced by future smart cities. However, how to effectively share sensor data without compromising confidentiality, privacy protection, and fair trading without third parties is one of critical issues that must be s...

A robust and scalable crowd management infrastructure is crucial in addressing operational challenges when deploying high-density sensors and actuators in a smart city. While crowdsourcing is widely used in crowd management, conventional solutions, such as Upwork and Amazon Mechanical Turk, generally depend on a trusted third-party platform. There...

Blockchain, a distributed ledger technology, can potentially be deployed in a wide range of applications. Among these applications, decentralized payment systems (e.g. Bitcoin) have been one of the most mature blockchain applications with widespread adoption. While the early designs (e.g. Bitcoin) are often the currency of choice by cybercriminals...

Increasingly, governments around the world, particularly in technologically advanced countries, are exploring or implementing smart homes, or the related smart facilities for the benefits of the society. The capability to remotely access and control Internet of Things (IoT) devices (e.g. capturing of images, audios and other information) is conveni...

The personal health record (PHR) service is a promising model for health data exchange. In practice, however, users’ health data need to be stored in an untrusted cloud server, which requires the design of a mechanism to achieve secure data sharing. Although the traditional attribute-based encryption (ABE) can be employed to facilitate PHR sharing...

Secure computation outsourcing in Internet of Things (IoT) system is an ongoing research challenge, partly due to the resource-constrained nature of most (inexpensive) IoT devices. In this paper, we focus on the secure outsourcing of bilinear pairings (SOBP) (the most computationally expensive operation in pairing-based cryptographic protocols / al...

To be prepared for the ‘Industry 4.0’-era, we propose a hierarchical framework comprising four tangible layers, which is designed to vertically integrate inter-organizational value networks, engineering value chain, manufacturing factories, etc. The conceptual framework allows us to efficiently implement a flexible and reconfigurable smart factory....

Blockchain can potentially be deployed in a wide range of applications due to its capability to ensure decentralisation, transparency and immutability. In this paper, we design a cryptographic membership authentication scheme (i.e. authenticating graph data) to support blockchain-based identity management systems (BIMS). Such a system is designed t...

A Universal Designated Verifier Transitive Signature (UDVTS) scheme is designed for the graph-based big data system. Specifically, it allows a transitive signature holder to convince the designated verifier with a transitive signature. Nevertheless, existing UDVTS schemes cannot be directly employed in the scenarios when multi-verifier are involved...

A recent trend in both industry and research is the Internet of Drones, which has applications in both civilian and military settings. However, drones (also known as unmanned aerial vehicles) are generally not designed with security in mind, and there are fundamental security and privacy issues that need study. Hence, in this article, we study the...

Motivated by the research of privacy protection in the graph-based big data system, we propose a new signature scheme. The properties of the constructed signature scheme are twofold. On one hand, it is consistent with the requests of the proxy signatures. Our method allows a signer to delegate his/her signing right to another user in such a way tha...

A recent trend in both industry and research is the Internet of Drones, which has applications in both civilian and military settings. However, drones (also known as unmanned aerial vehicles) are generally not designed with security in mind, and there are fundamental security and privacy issues that need study. Hence, in this article, we study the...

Statistical learning has been widely used in many fields, such as science, engineering and finance, to extract important patterns, trends, and understand “what the data say”. Privacy of statistical learning, i.e., user and sensitive data, is significant problem of performing computation, especially outsourcing cloud computing. Some fully homomorphi...

We present a novel design for stateless transitive signature (\(\mathrm {TS}\)) for undirected graph to authenticate dynamically growing graph data. Our construction is built on the widely studied \(\mathrm {ZSS}\) signature technology [19] with bilinear mapping, and using general cryptographic hash functions (e.g., \(\mathrm {SHA}\)-512 and \(\mat...

We propose a new design of universal designated verifier transitive signatures, to authenticate dynamically growing big graph data. The scheme is built on the classical RSA signature and possesses several desirable properties. It supports edge-signature composition as transitive signatures, i.e., with the signatures of two adjacent edges . (i,j) an...