Rough set theory, as one of the most useful soft computing methods dealing with vague and uncertain information, has been successfully applied to many fields, and one of its main applications is to ...perform attribute reduction. Although many heuristic attribute reduction algorithms have been proposed within the framework of the rough set theory, these methods are still computationally time consuming. In order to overcome this deficit, we propose, in this paper, two quick feature selection algorithms based on the neighbor inconsistent pair, which can reduce the time consumed in finding a reduct. At first, we propose several concepts regarding simplified decision table(U') and neighbor inconsistent pairs. Based on neighbor inconsistent pairs, we constructed two new attribute significance measures. Furthermore, we put forward two new attribute reduction algorithms based on quick neighbor inconsistent pairs. The key characteristic of the presented algorithms is that they only need to calculate U'/R once under the process of selecting the best attribute from attribute sets: C - R, while most existing algorithms need to calculate partition of U' for |C - R| times. In addition, the proposed algorithms need only to deal with the equivalent classes in U'/R that contain at least one neighbor inconsistent pair, while most existing algorithms need to consider all objects in U'. The experimental results show that the proposed algorithms are feasible and efficient.
Attribute reduction is one of the biggest challenges encountered in computational intelligence, data mining, pattern recognition, and machine learning. Effective in feature selection as the rough set ...theory is, it can only handle symbolic attributes. In order to overcome this drawback, the fuzzy rough set model is proposed, which is an extended model of rough sets and is able to deal with imprecision and uncertainty in both symbolic and numerical attributes. The existing attribute selection algorithms based on the fuzzy rough set model mainly take the angle of "attribute set," which means they define the object function representing the predictive ability for an attribute subset with regard to the domain of discourse, rather than following the view of an "object pair." Algorithms from the viewpoint of the object pair can ignore the object pairs that are already discerned by the selected attribute subsets and, thus, need only to deal with part of object pairs instead of the whole object pairs from the discourse, which makes such algorithms more efficient in attribute selection. In this paper, we propose the concept of reduced maximal discernibility pairs, which directly adopts the perspective of the object pair in the framework of the fuzzy rough set model. Then, we develop two attribute selection algorithms, named as reduced maximal discernibility pairs selection and weighted reduced maximal discernibility pair selection, based on the reduced maximal discernibility pairs. Experiment results show that the proposed algorithms are effective and efficient in attribute selection.
By broadcasting messages about traffic status to vehicles wirelessly, a vehicular ad hoc network (VANET) can improve traffic safety and efficiency. To guarantee secure communication in VANETs, ...security and privacy issues must be addressed before their deployment. The conditional privacy-preserving authentication (CPPA) scheme is suitable for solving security and privacy-preserving problems in VANETs, because it supports both mutual authentication and privacy protection simultaneously. Many identity-based CPPA schemes for VANETs using bilinear pairings have been proposed over the last few years to enhance security or to improve performance. However, it is well known that the bilinear pairing operation is one of the most complex operations in modern cryptography. To achieve better performance and reduce computational complexity of information processing in VANET, the design of a CPPA scheme for the VANET environment that does not use bilinear paring becomes a challenge. To address this challenge, we propose a CPPA scheme for VANETs that does not use bilinear paring and we demonstrate that it could supports both the mutual authentication and the privacy protection simultaneously. Our proposed CPPA scheme retains most of the benefits obtained with the previously proposed CPPA schemes. Moreover, the proposed CPPA scheme yields a better performance in terms of computation cost and communication cost making it be suitable for use by the VANET safety-related applications.
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 security and privacy challenges by adding a significant cost on verification and traceability. As a result, current solutions fail to meet high mobility, low latency, and real-time requirements of VANETs. In this article, we design three new system building blocks namely key derivation (KeyDer), signatures of knowledge (SoK) and smart contract, following by a more efficient BCPPA protocol (named as EBCPA). To show the advantage of EBCPA, we first demonstrate it can satisfy the necessary requirements (e.g., message authentication, conditional privacy protection, resilience to common attacks, and so forth). Moreover, we implement the EBCPA in the on-line Ethereum test network (Rinkeby), Hyperledger test network and VANETs simulation environment (via VanetMobiSim and NS-2). Finally, we evaluate its communication overhead and computational cost via comparing to existing BCPPA protocols that strive to achieve similar properties. From the implementation and comparison results, our proposal can improve efficiency by reducing the time cost of traceability at least 48.95% and verification at least 42.21%.
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 been proposed. However, CPPA protocols are generally far from being ready for deployment in VANETs, for example due key/certificate management limitations in PKI-based protocols or intractable private key updating in ID-based protocols. Although serveral blockchain-based CPPA (BCPPA) protocols have been proposed to mitigiate these challenges, there still exist some intractabilities such as revoking private key, or frequent interactions, or requiring an idea hardware. Thus, in this paper, we are motivated to propose a novel BCPPA protocol without these existing issues. Specifically, we present a PKI-based solution (using a typical digital signature protocol, such as ECDSA) based on Ethereum (a public blockchain), which is designed to facilitate secure communication in VANETs. In other words, we combine the blockchain technology and a key derivation algorithm to realize an effective certificate management. This reduces the need for participating vehicles to store a large number of private keys. To reduce the verification time cost, our BCPPA suppotrs replacing ECDSA with modified ECDSA for batch verification or directly adopting other PKI-based signatures with batch verification. In addition to introducing the concrete design, we also present the security requirements that our BCPPA protocol can satisfy. We then implement BCPPA in the Ethereum test network (i.e. Rinkeby ) and provide simulations using VanetMobiSim and NS-2 to show its feasibility (i.e. milliseconds).
Outsourcing computations have been widely used to meet the growing computing demands, although achieving trust in an untrusted (or a zero-trust) environment can be challenging in practice. Fair ...payment, a candidate solution, can potentially facilitate fair trading among outsourcing computation participants such as users and workers. However, most existing solutions including traditional e-cash-based or blockchain-based, may potentially compromise the worker's fairness (i.e., does not achieve robust fairness, since trusted third parties are required during the trading process), or involve heavy zero-knowledge proofs (ZKPs, with significant computation costs). To mitigate these limitations, we propose a system model of an optimized blockchain-based fair payment (OBFP) for outsourcing computations. Then, we construct a ZKP-free solution based on blockchain by combining any secure commitment, accumulator, and symmetric encryption schemes, as well as a hash function. To demonstrate the utility of our proposed OBFP system, we provide security analysis, performance evaluation and a comparison with existing popular solutions. Specifically, the cryptographic tools are instantiated as commitment (Perdesen commitment), accumulator (RSA-based accumulator), and symmetric encryption (a concrete scheme with the indistinguishability under chosen-plaintext attack (IND-CPA) security), and a hash function (Keccak-256). The prototype is implemented in COSBench and Remix to analyze cloud scalability and concurrency, as well as gas cost.
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. However, we need to consider security inherent in existing (stand-alone) devices and networks as well as those that may arise in such integrations. Especially the existing solutions are insufficient to address these fundamental security concerns. Thus, we present a blockchain-based system for secure mutual authentication, BSeIn, to enforce fine-grained access control polices. The proposed system (with integrated attribute signature, multi-receivers encryption and message authentication code) is designed to provide privacy and security guarantees such as anonymous authentication, auditability, and confidentiality. BSeIn also scales well due to the utilization of smart contract. We then evaluate the security and performance of BSeIn. For example, findings from the performance evaluation demonstrate that Initialization/Request Issuance/Chain Transaction/State Delivery/Permission Update phase only cost 12.123/4.810/6.978/0.013/2.559s, respectively.
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 the digital signatures they employ. Universal Designated Verifier Signature Proof (UDVSP) may be an intuitive solution, but existing UDVSP schemes are inefficient due to time-consuming bilinear pairing operations. In this article, we first adopt the Elliptic Curve Digital Signature Algorithm (ECDSA) to propose a more efficient and blockchain-friendly UDVSP scheme, following by a blockchain-based EMR sharing system (EMRChain). To our best knowledge, our proposed UDVSP scheme is the first bilinear pairing-free solution, and EMRChain is the first blockchain-based EMR sharing system to possess the anti-malicious propagation. Furthermore, we proceed to provide a thorough security analysis and performance evaluation of both our UDVSP scheme and EMRChain. Our UDVSP scheme is provably secure within the security model and offers significant computational cost savings (at least 86.76%) and reduced communication overhead (at least 59.37%) compared to existing UDVSP schemes. These results, along with the EMRChain prototype, effectively showcase the utility and effectiveness of EMRChain, which is built upon our UDVSP scheme.
Automatic dependent surveillance–broadcast (ADS-B) serves as a fundamental component of the next-generation national airspace strategies in numerous states, facilitating the improvement and ...modernization of aviation infrastructure and operations. Within the ADS-B system, an aircraft (AC) equipped with ADS-B technology periodically transmits and shares information with ground-based stations and fellow ACs through open communication channels. Yet, the employment of plaintext communication on open channels exposes ADS-B systems to security vulnerabilities, including the potential for message tampering and interception. To protect the authenticity and integrity of messages conveyed through the ADS-B system, a range of hierarchical identity-based signature (HIBS) schemes have been put forth. Nonetheless, current solutions exhibit certain shortcomings, including issues like excessive computational demands, incapacity to support batch signature verification, and less-than-optimal security guarantees. To remedy these shortcomings, we put forth a secure and effective HIBS scheme. We offer a thorough security proof that our scheme fulfills the existential unforgeability against selective identity and chosen-message attacks under the standard model. Furthermore, we have undertaken experiments to assess and contrast our proposed approach with various existing alternatives, and the findings indicate that our solution is better suited to meet the specific demands imposed by the ADS-B system.
•We analyze the limitations in existing SOBP-based schemes, such as the one-malicious model (Strong Assumption), a secure channel (Insufficiency), and a trusted server (Centralization).•We propose a ...novel blockchain-based system for SOBP based on a permissioned version (i.e. a blockchain ledger maintained by some permissioned nodes), to efficiently address the limitations.•We prove our proposed approach in a one trusted program model and implement it on Ethereum (an open-source blockchain system) to show its utility.
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 / algorithms). First, we analyze the limitations in existing SOBP-based schemes, such as the one-malicious model (Strong Assumption), a secure channel (Insufficiency), and a trusted server (Centralization). Then, we propose a novel blockchain-based system for SOBP based on a permissioned version (i.e., a blockchain ledger maintained by some permissioned nodes), designed to efficiently address the limitations. Finally, we prove the security of our proposed approach in the one untrusted program model and implement it on Ethereum (an open-source blockchain system) to show its utility.
