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Cloud-assisted Industrial Internet of Things (IIoT) gathers and analyzes multiple types of data (such as ambient and mechanical data) from physical devices to improve intelligent manufacturing. However, the heavy requirements for data storage and sharing have led to increased demands for efficiency and security in the IIoT system. Public-key Encryption with Keyword Search (PEKS) is an encryption method that provides both data confidentiality and efficient retrieval. Unfortunately, inside keyword guessing attacks (IKGA) have been a persistent issue in PEKS. To resist this attack, Public-key Authenticated Encryption with Keyword Search (PAEKS) has been developed. However, the existing PAEKS schemes are generally proven under intractability assumptions, such as Decisional Bilinear Diffie-Hellman (DBDH) and modified Decision Linear (mDLIN) assumptions, or they involve costly bilinear pairing operations, or rely on two non-colluded cloud servers, which are not suitable for large-scale IIoT applications. In this article, we propose a secure and efficient PAEKS scheme with only one server for cloud-assisted IIoT. Our proposal achieves the IKGA-secure property (i.e., it satisfies the trapdoor privacy and multi-ciphertext indistinguishability) and sidesteps the bilinear pairing operation. Our performance analysis demonstrates the feasibility of our scheme in IIoT by significantly improving computation efficiency (at least 21.97 times) with similar communication overhead.

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 w86.76%) 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.

With the development of quantum computing, the existing cryptography schemes based on classical cryptographic primitives will no longer be secure. Hence, cryptographers are designing post-quantum cryptographic (PQC) schemes, and ideal lattice-based cryptography has emerged as a prime candidate. Today, as ideal lattice-based cryptography becomes more mature, its performance becomes an important optimization goal. In ideal lattice-based cryptography, polynomial arithmetic and polynomial sampling are the most timeconsuming operations and therefore need to be accelerated. In this article, taking advantage of the parallelism of new 512-bit advanced vector instructions (AVX512), we present parallel implementations of polynomial arithmetic and polynomial sampling, thus comprehensively improving their performance. We conduct experiments with the Dilithium scheme(one scheme of NIST PQC Standardization Process Round-4). Our implementation gets a nice performance boost compared to its pure C language and 256-bit advanced vector instructions (AVX2) implementation.

Despite the myriad benefits offered by blockchain technology, most of them still face several interrelated issues, such as limited transaction throughput, exorbitant transaction fees, and protracted confirmation times. Payment channel networks have emerged as a promising scalability solution, allowing two mutually distrustful users to engage in multiple off-chain transactions. However, existing schemes based on Hash Time Lock Contract or Anonymous Multi-hop Lock generally cannot ensure strong unlinkability of payments, due to the fact that the time-lock information still remains on the blockchain. To enhance on-chain privacy, a versatile tool was recently proposed by Thyagarajan et al. (CCS'20), named Verifiable Timed Signatures, but it suffers from the dual insufficiencies of linear-increasing performance and time unverifiability (i.e., performance is linear to the number of signature shares, and signatures cannot be ensured recoverable after the specified time). In this paper, we first propose an approach to reduce computational overhead of VTS, which can be applied to enhance other established schemes, such as VTD (S&P'22) and VTLRS (ESORICS'22). To further reduce the computational complexity from O(n) to O(1), we introduce a new cryptographic primitive called Verifiable Timed Adaptor Signatures. Moreover, we extend the VTAS to VTAS(+) which provides the security property of verifiable recovery. We demonstrate the practicality of our proposal via presenting a concrete instantiation and constructing a privacy-enhanced payment channel network. Finally, the comprehensive evaluation reveals that our solutions exhibit superior performance than the state-of-the-art schemes.

In crowdsensing, we can leverage intelligent devices and real-time incentive mechanisms to facilitate the collection of reliable and timely data in Industrial Internet of Things (IIoT) settings. In such a setting, one can use cryptographic primitives to support data privacy preservation and quality-aware reward distribution simultaneously. However, existing approaches might incur expensive computation costs, suffer from overflow problems, or rely on implicit security conditions. In this paper, we propose an fficient and rivacy-preserving eal-time ncentive system for rowdsnsing (EPRICE), designed to estimate the reliability of sensing data in a privacy-preserving setting. The theoretical analysis demonstrates that our proposed system achieves a high level of privacy-preserving for real-time reward distribution and supports practical privacy-preserving properties. The experimental findings show that our proposed EPRICE system significantly decreases the computation costs by compared with other competing schemes.

Identity-based cryptography is proposed to solve the complicated certificate management of traditional public-key cryptography. The pairing computation and high-level tower extension field arithmetic turn out to be the performance bottleneck of pairing-based signature schemes. Graphics processing units have been increasingly popular for general-purpose computing in recent years. They have shown a lot of promise in speeding up cryptographic schemes such as AES, RSA, and ECDSA. However, to our knowledge, the research on parallel implementation of pairings and identity-based cryptographic schemes on graphics processing units is somewhat outdated. Therefore, in this article, we implement the identity-based signature scheme in the IEEE P1363 Standard on a modern NVIDIA RTX 3060 card. We convert the pairing computation in signature verification into a product of pairings with fixed arguments and therefore avoid the scalar multiplication in G(2). Then we employ the precomputation technique to improve the elliptic curve scalar multiplication, exponentiation in F-p(12) and the pairing computation. We also apply PTX ISA to multiple-precision arithmetic. Experiments demonstrate that our implementation can perform 43,856/46,753/39,798 pairings/sec for the Optimal Ate pairing, the pairing with a fixed argument, and two pairings with fixed arguments, respectively. Peak throughputs of signature generation and verification can achieve 322.6 and 40.6 kops/sec over the BN254 curve.