Key Leakage Research Articles

A Content-Assisted Dynamic PUF Key Generation Scheme Using Compressive Autoencoder for Internet-of-Things

A physical unclonable function (PUF) is broadly investigated as a secret key generator for internet-of-things (IoT) devices because of its uniqueness and randomness. Security vulnerability may occur in conventional PUF-based schemes if an attacker eavesdrops on the challenge and response pair (CRP) associated with PUF. To mitigate the impact of such key compromise, this study proposes a novel dynamic PUF key generation scheme, where the sensing data-based dynamic features are integrated to a static PUF-based key. The compressive autoencoders (AEs) typically employed for compressing the time-series data can be customized to extract data-based features. The dynamic features are quantized to generate the data-based key, and then combined with the PUF-based key for the dynamic key generation. An attacker finds it difficult to extract the PUF-based key from the synthesized ones; hence, CRPs cannot be estimated, even if the attacker can obtain the dynamic key through eavesdropping. The event signal decomposition algorithm, which disjoins the dominant event signal in the dataset, is proposed to enhance the data-based key diversity. For numerical evaluation, the static random access memory-PUF and the public energy dataset are used for the dynamic key generation. Numerical results show that the AE model can generate a data-based key that prohibits key leakage to the attacker while improving the reconstruction performance. The dynamic key is evaluated for diverse attack models (e.g., replay and modeling attacks), and the attacker cannot estimate the CRP tables.

Lattices-Inspired CP-ABE from LWE Scheme for Data Access and Sharing Based on Blockchain

To address the quantum attacks on number theory-based ciphertext policy attribute-based encryption (CP-ABE), and to avoid private key leakage problems by relying on a trustworthy central authority, we propose a lattice-inspired CP-ABE scheme for data access and sharing based on blockchain in this paper. Firstly, a CP-ABE-based algorithm using learning with errors (LWE) assumption is constructed, which is selective security under linear independence restriction in the random oracle model. Secondly, the blockchain nodes can act as a distributed key management server to offer control over master keys used to generate private keys for different data users that reflect their attributes through launching transactions on the blockchain system. Finally, we develop smart contracts for proving the correctness of proxy re-encryption (PRE) and provide auditability for the whole data-sharing process. Compared with the traditional CP-ABE algorithm, the post-quantum CP-ABE algorithm can significantly improve the computation speed according to the result of the functional and experimental analysis. Moreover, the proposed blockchain-based CP-ABE scheme provides not only multi-cryptography collaboration to enhance the security of data access and sharing but also reduces average transaction response time and throughput.

An anti-collusion attack defense method for physical layer key generation scheme based on transmission delay.

Physical layer security (PLS) is considered one of the most promising solutions to solve the security problems of massive Internet of Things (IoTs) devices because of its lightweight and high efficiency. Significantly, the recent physical layer key generation (PLKG) scheme based on transmission delay proposed by Huang et al. (2021) does not have any restrictions on communication methods and can extend the traditional physical layer security based on wireless channels to the whole Internet scene. However, the secret-sharing strategy adopted in this scheme has hidden dangers of collusion attack, which may lead to security problems such as information tampering and privacy disclosure. By establishing a probability model, this article quantitatively analyzes the relationship between the number of malicious collusion nodes and the probability of key exposure, which proves the existence of this security problem. In order to solve the problem of collusion attack in Huang et al.'s scheme, this article proposes an anti-collusion attack defense method, which minimizes the influence of collusion attack on key security by optimizing parameters including the number of the middle forwarding nodes, the random forwarding times, the time delay measurement times and the out-of-control rate of forwarding nodes. Finally, based on the game model, we prove that the defense method proposed in this article can reduce the risk of key leakage to zero under the scenario of the "Careless Defender" and "Cautious Defender" respectively.

A lightweight CP‐ABE scheme in the IEEEP1363 standard with key tracing and verification and its application on the Internet of Vehicles

AbstractAutomated vehicle applications are becoming more and more widespread, and the data security of the vehicle network involved is particularly important. Similar to traditional data, the characteristics of autonomous driving data security are mainly confidentiality, integrity, and availability. If data related to autonomous driving is stolen or tampered with, it will directly cause loss of property or life, which is more harmful than traditional data destruction. To address the security issues on the Internet of Vehicles, we propose an encryption (CP‐ABE) scheme which is ciphertext policy attribute‐based and lightweight. And it can provide fine‐grained access control to data on the Internet of Vehicles with less computational overhead on the device itself, making it ideal for the Internet of Vehicles environment. The scheme also supports key traceability to address the user key leakage problem. Experiments show that the proposed system is effective.

Mobile DMA testing for leakage assessment: perspectives from Ontario, Canada

Abstract The formation of discrete regions in a water distribution system, referred to as district metered areas (DMAs), can be a pragmatic approach to diagnose both system and leakage characteristics. Their application, however, has historically been limited in the North American context owing in part to their costly implementation and operational challenges. Both to overcome these barriers and to demonstrate the benefits of DMAs, a leakage testing programme was undertaken in Ontario, Canada. Novelty arises from the development and deployment of a mobile testing unit specifically designed to collect minimum night flow (MNF) and pressure data into temporarily configured DMAs. Moreover, activation of a pressure reducing valve facilitated the direct testing of pressure modulation on leakage reduction. The mobile unit was deployed in 22 DMAs across eight water systems with results indicating a clear relationship between MNFs and system characteristics for well-performing DMAs. MNF benchmarks were quantified to enable an evidence-based assessment of leakage performance at the DMA level in typical Canadian water systems. This project established the proof-of-concept of the mobile unit for providing both accurate and reliable measurements of key leakage performance characteristics and for predicting leakage reduction following system interventions.

Lattice-based group signatures with forward security for anonymous authentication

Group signatures allow users to sign messages on behalf of a group without revealing authority is capable of identifying the user who generated it. However, the exposure of the user's signing key will severely damage the group signature scheme. In order to reduce the loss caused by signing key leakage, Song proposed the first forward-secure group signature. If a group signing key is revealed at the current time period, the previous signing key will not be affected. This means that the attacker cannot forge group signatures regarding messages signed in the past. To resist quantum attacks, many lattice-based forward-secure group signatures have been proposed. However, their key-update algorithm is expensive since they require some costly computations such as the Hermite normal form (HNF) operations and conversion from a full-rank set of lattice vectors into a basis.In this paper, we propose the group signature with forward security from lattice. In comparison with previous works, we have several advantages: Firstly, our scheme is more effective since we only need to sample some vectors independently from a discrete Gaussian during the key-update algorithm. Secondly, the derived secret key size is linear instead of quadratic with the lattice dimensions, which is more friendly towards lightweight applications. Anonymous authentication plays an increasingly critical role in protecting privacy and security in the environment where private information could be collected for intelligent analysis. Our work contributes to the anonymous authentication in the post-quantum setting, which has wide potential applications in the IoT environment.

A Novel Revocable Lightweight Authentication Scheme for Resource-Constrained Devices in Cyber–Physical Power Systems

The existing identity security schemes (e.g., based on bilinear pairing) have high computational complexity and large bytes of variables, which results in high computation and communication costs. It is difficult to apply the schemes to resource-constrained (i.e., computation and communication) devices. Moreover, most of these schemes adopt a fixed cycle key update strategy compromising the security of authentication schemes or dynamic (real-time) key update strategy with high computational cost. To solve these issues, this article explores a novel revocable lightweight authentication scheme for resource-constrained devices in cyber–physical power systems (CPPSs). First, a lightweight authentication scheme combined elliptic-curve cryptography (ECC) and certificateless cryptography (CLC) is proposed to negotiate a secure session key, which can achieve mutual authentication with low computation and communication costs. Second, aiming at security problem caused by key leakage, a real-time key update strategy with low computational cost is designed to improve the security of identity authentication. Third, according to a hardness assumption of the elliptic-curve discrete logarithm problem (ECDLP), theoretical analysis rigorously proves that the proposed authentication scheme ensures the security with respect to existential unforgeability against adaptively chosen message attacks (EUF-CMAs). Finally, experimental results confirm the feasibility and effectiveness of the proposed authentication scheme.

An Efficient Cryptographic Scheme for Securing Time-Sensitive Microgrid Communications Under Key Leakage and Dishonest Insiders

Cryptographic schemes are often deployed in microgrids to protect communication security. However, most existing schemes widely used in microgrids cannot ensure forward secrecy and non-repudiation under key leakage and dishonest insiders. Although some existing cryptographic techniques can theoretically overcome these vulnerabilities, their computational complexity may significantly extend the communication latency, making them less suitable for the time-sensitive microgrid control scenario. In this paper, a novel cryptographic scheme is proposed to guarantee not only confidentiality and integrity but also forward secrecy and non-repudiation of microgrid control communications. Built from key-evolving symmetric encryption and online/offline signature, the scheme can efficiently run in embedded controllers with limited computational resources. The security of the scheme is analyzed in the paper, with a recommended instantiation given through comprehensive comparisons of candidate cryptographic algorithms. Besides, the effectiveness and efficiency of the proposed scheme are tested on a microgrid model through cyber-physical co-simulation.

Discussion of “Ultra Super Fast Authentication Protocol for Electric Vehicle Charging Using Extended Chaotic Maps”

Recently, Wang et al. proposed an ultra super fast authentication protocol for electric vehicle charging (IEEE Transactions on Industry Applications, 2022, DOI: 10.1109/TIA.2022.3184668). The authors claimed that their protocol is secure and can resist known security attacks. However, in this comment paper, we demonstrate that their protocol is still vulnerable to session key leakage. In addition, we found that it has incorrect electric vehicle owner registration phase and mutual authentication and key agreement phase.

Finite-key analysis of decoy model semi-quantum key distribution based on four-state protocol

Semi-quantum key distribution allows a full quantum user Alice and a classical user Bob to share a pair of security keys guaranteed by physical principles. Semi-quantum key distribution is proposed while verifying its robustness. Subsequently, its unconditional security of semi-quantum key distribution system is verified theoretically. In 2021, the feasibility of semi-quantum key distribution system based on mirror protocol was verified experimentally. However, the feasibility experimental system still uses the laser pulse with strong attenuation. It has been proved in the literature that the semi-quantum key distribution system still encounters the risk of secret key leakage under photon number splitting attack. Therefore, the actual security of key distribution can be further reasonably evaluated by introducing the temptation state and conducting the finite-key analysis in the key distribution process. In this work, for the model of adding one-decoy state only to Alice at the sending based on a four state semi-quantum key distribution system, the length of the security key in the case of finite-key is analyzed by using Hoeffding inequality, and then the formula of the security key rate is obtained. It is found in the numerical simulation that when the sample size is <inline-formula><tex-math id="M3">\begin{document}$ {10}^{5} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20230849_M3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20230849_M3.png"/></alternatives></inline-formula>, the security key rate of <inline-formula><tex-math id="M4">\begin{document}$ {10}^{-4} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20230849_M4.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22-20230849_M4.png"/></alternatives></inline-formula>, which is close to the security key rate of the asymptotic limits, can be obtained in the case of close range. It is very important for the practical application of semi-quantum key distribution system.

Device capture resilient authentication and key agreement protocol for IoV

With the steady growth of car ownership and the saturation of road traffic, the Internet of vehicle (IoV) is regarded as one of the most effective technologies to improve traffic efficiency and driving experience. Authentication and key agreement protocol (AKA) is a key means to ensure secure interaction between the onboard unit (OBU) and the various information servers. Typically, the private key of AKA protocol is stored in the OBU. However, OBU theft occurs as vehicles are often left unattended. Therefore, it is a challenge to ensure the secure storage of private keys. To address the above problem, a capture-resistant AKA protocol based on oblivious pseudorandom functions (OPRF) and collaborative signature is proposed in this paper. The private key is divided into two parts, one is encrypted using the public key of the auxiliary device and another can only be recovered by running the OPRF protocol between the OBU and the auxiliary device. Since no secret information is stored in the OBU, the adversary cannot obtain the private key even if the OBU is stolen. The comprehensive security analysis and performance comparison of the proposed scheme is provided in this paper. The result demonstrates that the proposed scheme is resistant to various known attacks, especially key leakage caused by device capture. In addition, the proposed scheme can strike a balance between computational and communication overhead.

Efficient CP-ABE Scheme Resistant to Key Leakage for Secure Cloud-Fog Computing

<p>With the evolution of the Internet, people’s lives are growing increasingly intelligent, and massive amounts of data are also generated. The combination of cloud computing and fog computing can store and process it efficiently. However, a new and urgent challenge has emerged about how to ensure that data in cloud and fog nodes are accessed securely. In order to address this issue, we propose an efficient anti-key leakage CP-ABE (EAL-CP-ABE) scheme based on cloud-fog computing. In our scheme, we achieve the identity tracing of the authorized user who leaked the private key by means of white-box tracing and the maximum number of user accesses. Meanwhile, we design a reward and punishment mechanism which rewards those with a good reputation and revokes authorized users who have exceeded the access limit or sold private keys to further reduce the possibility of key leakage. Due to limited local resources, we use fog nodes to achieve outsourced decryption of ciphertext. In addition, the detailed security analysis is provided to prove that the EAL-CP-ABE scheme is IND-CPA secure and traceable based on the hardness assumptions. Finally, we demonstrate that the EAL-CP-ABE scheme is efficient through the performance analysis.</p> <p> </p>

Continuous Leakage-resilient and Hierarchical Identity-based Online/Offline Encryption

<p>By dividing encryption as online and offline stages, the online/offline encryption schemes are very suitable to lightweight equipment. For the offline stage, high-performance equipment is used for complex preprocessing calculation, and the online stage the lightweight devices only make some simple calculations. In addition, side channel attacks can disclose some secret information of the cryptosystem, which leads to the destruction of the security of the cryptography schemes. Most of the online/offline identity-based encryption schemes cannot resist side channel attacks. The paper proposes a concrete hierarchical identity-based and online/offline encryption scheme that can resist continuous leakage of secret key. By the dual system encryption technology, we prove that the given scheme is fully secure. Through key updation technology, our proposed scheme resists continual leakage of private key. The relative leakage rate of the private key can reach 1/3. In addition, the presented scheme has the hierarchical function which effectively solves the problem of heavy load in a single key generation center. The given scheme is suitable for applications in distributed environment.</p> <p> </p>

Cryptanalysis and Improvement of DeepPAR: Privacy-Preserving and Asynchronous Deep Learning for Industrial IoT

Industrial Internet of Things (IIoT) is gradually changing the mode of traditional industries with the rapid development of big data. Besides, thanks to the development of deep learning, it can be used to extract useful knowledge from the large amount of data in the IIoT to help improve production and service quality. However, the lack of large-scale data sets will lead to low performance and overfitting of learning models. Therefore, federated deep learning with distributed data sets has been proposed. Nevertheless, the research has shown that federated learning can also leak the private data of participants. In IIoT, once the privacy of participants in some special application scenarios is leaked, it will directly affect national security and people’s lives, such as smart power grid and smart medical care. At present, several privacy-preserving federated learning schemes have been proposed to preserve data privacy of participants, but security issues prevent them from being fully applied. In this article, we analyze the security of the DeepPAR scheme proposed by Zhang et al., and point out that the scheme is insecure in the re-encryption key generation process, which will cause the leakage of the secret key of participants or the proxy server. In addition, the scheme is not resistant to collusion attacks between the parameter server and participants. Based on this, we propose an improved scheme. The security proof shows that the improved scheme solves the security problem of the original scheme and is resistant to collusion attacks. Finally, the security and accuracy of the scheme is illustrated by performance analysis.

Untouchable Once Revoking: A Practical and Secure Dynamic EHR Sharing System via Cloud

Healthcare Internet-of-Things (IoT) enables lightweight devices to observe patients’ vital signals and outsource them to a remote cloud to enjoy flexible data sharing. However, it faces many security threats as the outsourced data is no longer physically controlled by data owners, and the cloud that hosts the outsourced data is not fully trusted. Many privacy protection technologies have been adopted to solve this problem, among which cryptographic mechanisms have become one of the most promising tools. Unfortunately, current cryptographic mechanisms in healthcare IoT mainly suffer from the following challenges: 1) dynamic user groups for managing users’ accessibility; 2) efficient revocation mechanism to mitigate the burden during user revocation; 3) forward and backward secrecy to ensure session independence in the presence of session key leakage; 4) revocable storage to prevent data users from learning any unauthorized data even the data is authorized before; and 5) information manipulation during data transmission. In this article, we introduce a practical and secure system to address the above problems. Our system provides fine-grained access control with dynamic user groups for optimizing scalability and functionality. We prove that our system is secure against numerous real-world threats. Extensive comparison and experimental analysis demonstrate that our system enjoys superior performance than the state-of-the-art solutions.

An efficient conditional privacy-preserving authentication scheme with scalable revocation for VANETs

In Vehicular Ad Hoc Networks (VANETs), secure information sharing between vehicles is critical for improving traffic efficiency and driving safety. However, existing identity-based communication protocols for VANETs face problems of over-reliance on ideal Tamper-Proof Devices (TPDs) and the efficiency of verifying multiple messages in areas of high traffic density. Besides, many existing authentication schemes suffer from the heavy workload of revoking malicious vehicles when they misbehave. For addressing these problems, we propose an efficient Identity-Based conditional privacy-preserving authentication protocol, which does not rely on the ideal TPD. In our scheme, the System Secret Key (SSK) is not directly preloaded with the TPD, thus avoiding a system crash when a vehicle is corrupted. To revoke malicious vehicles’ identity, we propose an efficient key updating method based on Shamir’s secret sharing algorithm, which improves key-update efficiency from linear to logarithmic in the number of unrevoked vehicles. Moreover, our scheme is based on Elliptic Curves Cryptosystem and avoids bilinear pairing operation while supporting batch verification, enabling faster verification even when the number of signatures is increasing. According to the results of exhaustive comparative analysis, our proposed scheme is secure against key leakage attack and efficient in overhead of computation and communication compared to related schemes.

An Efficient Blockchain-Based Hierarchical Data Sharing for Healthcare Internet of Things

With the assistance of the Internet of Things, the fast developing Healthcare Internet of Things (H-IoT) has promoted the healthcare ecosystem into the era of Health 5.0 and enables many promising medical applications, such as remote healthcare that is crucial in pandemic (e.g., coronavirus disease 2019). Healthcare participants can make accurate diagnosis, treatment, and research based on the shared personal health records (PHRs) sensed from remote H-IoT devices. However, current H-IoT systems fall short of a secure and trustworthy PHR sharing service in remote healthcare, which is able to prevent user privacy leakage and PHR integrity violation together with high efficiency in key distribution alongside efficient data retrieval and fine-grained access control. In response, we present a blockchain-based hierarchical data sharing framework (BHDSF) to provide fine-grained access control and efficient retrieval over encrypted PHRs with low consumed hierarchical key distribution and key leakage resistance. Compared with the existing solutions, the BHDSF takes both untrusted cloud and malicious auditor into consideration simultaneously and achieves trustworthy PHR integrity auditing and metadata verification by leveraging the blockchain technique. Besides, the BHDSF enables efficiently aggregative authentication for the trustworthiness of source records from H-IoT devices, which is lacked in most of the existing data sharing frameworks. Finally, we demonstrate the feasibility of the BHDSF by conducting extensive empirical tests over a real-world dataset.

Public-key encryption scheme with optimal continuous leakage resilience

In real-world applications, adversaries can launch leakage attacks, such as side-channel attacks, to obtain some information of the secret states (e.g. secret key, random value, etc.) in cryptographic protocols, compromising their security. Moreover, adversaries can obtain more leakage information by performing leakage attacks continuously, and the leakage attacks can be performed at any time by the adversary. Therefore, when designing public-key encryption (PKE) schemes, one should consider the continuous leakage setting. And it is desirable that the designed schemes can resist the leakage attacks. In this paper, to achieve better continuous leakage resilience, a novel construction of continuous leakage-resilient PKE scheme is proposed. The chosen-ciphertext attacks security of our proposed scheme can be proved based on the hardness of the decisional Diffie-Hellman assumption. Our construction tolerates a large key leakage rate, which is one of the best among existing PKE schemes. Moreover, the level of leakage resilience can be adjusted based on the specific requirements in real-world applications. The analyses demonstrate that our proposal also enjoys low computational overheads, outperforming the existing leakage-resilient PKE schemes.

A Privacy-Preserved ID-Based Secure Communication Scheme in 5G-IoT Telemedicine Systems.

5G networks have an efficient effect in providing quality of experience and massive Internet of things (IoT) communication. Applications of 5G-IoT networks have been expanded rapidly, including in smart medical healthcare. Emergency medical services (EMS) hold an assignable proportion in our lives, which has become a complex network of all types of professionals, including care in an ambulance. A 5G network with EMS can simplify the medical treatment process and improve the efficiency of patient treatment. The importance of healthcare-related privacy preservation is rising. If the work of privacy preservation fails, not only will medical institutes have economic and credibility losses but also property losses and even the lives of patients will be harmed. This paper proposes a privacy-preserved ID-based secure communication scheme in 5G-IoT telemedicine systems that can achieve the features below. (i) The proposed scheme is the first scheme that integrates the process of telemedicine systems and EMS; (ii) the proposed scheme allows emergency signals to be transmitted immediately with decreasing risk of secret key leakage; (iii) the information of the patient and their prehospital treatments can be transmitted securely while transferring the patient to the destination medical institute; (iv) the quality of healthcare services can be assured while preserving the privacy of the patient; (v) the proposed scheme supports not only normal situations but also emergencies. (vi) the proposed scheme can resist potential attacks.

An Anonymous Authentication Protocol With Delegation and Revocation for Content Delivery Networks

By redirecting a user’s request to the nearest cache server, content delivery networks (CDNs) enable users to obtain services in time and reduce the burden of the origin server. Nevertheless, the origin server suffers from the private key leakage problem when delegating the authentication capability to untrusted CDN nodes. To handle this challenge, this article proposes an anonymous authentication protocol with delegation and revocation for CDNs depending on the proxy resignature (PRS) cryptography. Specifically, we first present an efficient revocable PRS (R-PRS) scheme, which is proved to be secure under the extended Computational Diffie-Hellman assumption. Then, based on R-PRS scheme, the proposed protocol enables the origin server to delegate and revoke the authentication capability to the CDN nodes without leaking its private key. Furthermore, our protocol not only provides anonymity, mutual authentication, and session key establishment, but also achieves forward security. Eventually, theoretical analysis and implementation demonstrate that the proposed protocol has an excellent performance in efficiency and practicality.