A LDPC codes based Authentication Scheme

The blockchain-enabled internet of medical things (IoMT) is an emerging paradigm that could provide strong trust establishment and ensure the traceability of data sharing in the IoMT networks. One of the fundamental building blocks for Blockchain is Elliptic Curve Digital Signature Algorithm (ECDSA). Nevertheless, when processing a large number of transactions, the verification of multiple signatures will incur cumbersome overhead to the nodes in Blockchain. Although batch verification is able to provide a promising approach that verifies multiple signatures simultaneously and efficiently, the upper bound of batch size is limited to small-scale and the efficiency will drop rapidly as the batch size grows in the state-of-the-art ECDSA batch schemes. Meanwhile, most of the existing researches only focus on improving the efficiency of batch verification algorithms in various cryptosystem while ignoring the identification of invalid signatures, which could cause severe performance degradation when the batch verification fails. Motivated by these observations, this paper proposes an efficient and large-scale batch verification scheme with group testing technology based on ECDSA. The application of the presented protocols in Bitcoin and Hyperledger Fabric has been analyzed as supportive and effective. When the batch verification returns a false result, we utilize group testing technology to improve the efficiency of identifying invalid signatures. Comprehensive simulation results demonstrate that our protocol outperforms the related ECDSA batch verification schemes.

In Eurocrypt 2007, Camenisch, Hohenberger and Pedersen introduced the notion of multi-signer batch verification and proposed several efficient and practical batch verification schemes for signatures, including a very efficient batch verification scheme for a multi-signer setting without random oracles. This scheme is the most efficient in comparison with other existing schemes, but it can be applied only to the multi-signer setting. We observe that amongst all existing batch verification schemes, the fastest scheme for a single-signer setting is based on the BLS short signature whose proof need resort to random oracles. It is clear that batch verification for a single-signer setting is as important as for multi-signer scenarios in some applications, especially where the system has only a single signer, such as a secure time-stamping server or a certificate generation server. However, to our knowledge, the efficient batch verification of short signatures in a single-signer setting without random oracles is a challenging open problem. In this paper, we propose a new signature scheme from Gentry IBE that is as efficient as the BLS short signature scheme in batch verification. We are able to prove its security without random oracles. Our signature is approximately 320 bits in length, and a verification requires only two pairings for verifying n signatures from a single signer.

IntroductionBlockchain technology has attracted much attention due to its decentralization, transparency and security. Initially applied in the financial field, it has now expanded to various fields such as Internet of Things (IoT), electronic cash and healthcare. However, the open nature of blockchain has raised potential security concerns about sensitive transaction data, and the increasing number of transactions requires low-latency solutions. Most blockchain applications still rely on the lightweight Elliptic Curve Digital Signature Algorithm (ECDSA). Due to complex operations such as vectorized multiplication and modular inversion, this may introduce significant additional overhead.MethodsTo address these issues, a new scheme named KTP-ECDSA is proposed. This scheme is based on the improved two-parameter Elliptic Curve Digital Signature Algorithm (TP-ECDSA) and the KGLP algorithm. In both the signing and verification processes, this scheme eliminates modular inverse operations and reduces scalar multiplications during the verification stage by using batch verification.ResultThe experimental results show that, compared with the traditional ECDSA, KTP-ECDSA has achieved a speed increase of over 50% in both independent verification and batch verification, significantly improving the efficiency of signature verification.DiscussionBy adopting the KTP-ECDSA algorithm and using the digital signature batch verification method, multiple signatures can be verified simultaneously, thus reducing the computational burden of the traditional single-verification method. This greatly increases the overall transaction throughput and improves resource utilization efficiency.

A SM2 based efficient and lightweight batch verification approach for IC cards

The Named-data Link State Routing protocol (NLSR) is an intra-domain routing protocol for Named Data Networking (NDN). It is an application level protocol similar with many IP routing protocols, but NLSR uses NDN's Interest/Data packets to disseminate the routing updates, directly benefit from NDN's built-in data authenticity. The security mechanism has been directly embedded inside the NDN protocol, thus a digital signature scheme is needed to check the integrity of each NLSR packets that exchanged between node that run NLSR. By default, NLSR uses RSA and ECDSA as digital signature algorithms that are proven to be efficient against attacks, but both have their respective advantages and disadvantages due to differences in computation and key methods used. The main purpose of our research was to find the optimal algorithm that give the best synchronization time during the signature scheme. Our experiment result show that RSA scheme performance speed is better than ECDSA scheme on NLSR in sync speed with 0.062558226% difference.

Named data networking (NDN) is an emerging information-centric networking paradigm, in which the Internet of Things (IoT) achieves excellent scalability. Recent literature proposes the concept of NDN-IoT, which maximizes the expansion of IoT applications by deploying NDN in the IoT. In the NDN, the security is built into the network by embedding a public signature in each data package to verify the authenticity and integrity of the content. However, signature schemes in the NDN-IoT environment are facing several challenges, such as signing security challenge for resource-constrained IoT end devices (EDs) and verification efficiency challenge for NDN routers. This article mainly studies the data package authentication scheme in the package-level security mechanism. Based on mobile edge computing (MEC), an efficient certificateless group signature scheme featured with anonymity, unforgeability, traceability, and key escrow resilience is proposed. The regional and edge architecture is utilized to solve the device management problem of IoT, reducing the risks of content pollution attacks from the data source. By offloading signature pressure to MEC servers, the contradiction between heavy overhead and shortage of ED resources is avoided. Moreover, the verification efficiency in NDN router is much improved via batch verification in the proposed scheme. Both security analysis and experimental simulations show that the proposed MEC-based certificateless group signature scheme is provably secure and practical.

The potential for vehicular ad hoc networks (VANETs) in improving traffic, enhancing road safety and reducing traffic accidents has attracted attention from academia, industry, and governments. To ensure secure communication in VANETs, a number of authentication schemes, including those with batch verification, were proposed in recent years. However, studies have demonstrated that most of the existing schemes suffer from bad performance or weak security. To address those problems, we construct a new identity-based digital signature (IBDS) scheme using bilinear pairings. The IBDS scheme is then used to construct a new identity-based conditional privacy-preserving authentication (IBCPPA) scheme for VANETs without the need for a map-to-point hash function or double secret keys. Using simulations, we demonstrate that our provably-secure IBCPPA scheme not only achieves better performance than related schemes, but also overcomes the inefficiency problem of the double secret keys in related schemes (i.e., the system does have to manage two secret keys to provide security).

The potential for vehicular ad hoc networks (VANETs) in improving traffic, enhancing road safety and reducing traffic accidents has attracted attention from academia, industry, and governments. To ensure secure communication in VANETs, a number of authentication schemes, including those with batch verification, were proposed in recent years. However, studies have demonstrated that most of the existing schemes suffer from bad performance or weak security. To address those problems, we construct a new identity-based digital signature (IBDS) scheme using bilinear pairings. The IBDS scheme is then used to construct a new identity-based conditional privacy-preserving authentication (IBCPPA) scheme for VANETs without the need for a map-to-point hash function or double secret keys. Using simulations, we demonstrate that our provably-secure IBCPPA scheme not only achieves better performance than related schemes, but also overcomes the inefficiency problem of the double secret keys in related schemes (i.e., the system does have to manage two secret keys to provide security).

Applications such as e-commerce payment protocols, electronic contract signing, and certified e-mail delivery require that fair exchange be assured. A fair-exchange protocol allows two parties to exchange items in a fair way so that either each party gets the other's item, or neither party does. We describe a novel method of constructing very efficient fair-exchange protocols by distributing the computation of RSA signatures. Specifically, we employ multisignatures based on the RSA-signature scheme. To date, the vast majority of fair-exchange protocols require the use of zero-knowledge proofs, which is the most computationally intensive part of the exchange protocol. Using the intrinsic features of our multisignature model, we construct protocols that require no zero-knowledge proofs in the exchange protocol. Use of zero-knowledge proofs is needed only in the protocol setup phase--this is a one-time cost. Furthermore, our scheme uses multisignatures that are compatible with the underlying standard (single-signer) signature scheme, which makes it possible to readily integrate the fair-exchange feature with existing e-commerce systems.

Digital Video Broadcasting-Terrestrial second generation (DVB-T2) systems are increasingly deployed for high quality terrestrial broadcasting. However, low Signal-to-Noise Ratio (SNR) conditions in urban and fringe coverage areas pose significant challenges, resulting in elevated Bit Error Rates (BER) and degraded service reliability. Forward Error Correction (FEC) techniques, particularly Low-Density Parity-Check (LDPC) and Bose Chaudhuri Hocquenghem (BCH) codes, play a crucial role in mitigating transmission errors and ensuring robust communication. This study investigates a systematic approach to optimizing LDPC and BCH FEC schemes to enhance transmission reliability and minimize BER under low-SNR conditions in DVB-T2 networks. Using simulation-based analyses, the study evaluates multiple LDPC code rates (e.g., 1/2, 2/3, 3/4) in combination with BCH codeword lengths and error-correcting capabilities. Results indicate that an optimized LDPC (64800, 32400) configuration combined with a BCH (255, 239) code significantly reduces BER, achieving approximately 10⁻⁵ at an SNR of 2 dB, compared to a BER of 10⁻³ using standard DVB-T2 FEC configurations. Additionally, iterative decoding algorithms for LDPC were fine-tuned to balance convergence speed and error correction performance, demonstrating a 25% reduction in decoding iterations without compromising reliability. The analysis also explores trade-offs between redundancy, throughput and latency, highlighting the practical considerations for real-world deployment. The findings underscore that strategic optimization of LDPC/BCH FEC parameters is critical for maintaining broadcast quality in low-SNR scenarios. By enhancing error resilience and reducing BER, the proposed approach improves signal integrity, supports consistent reception in fringe areas and maximizes spectrum efficiency. This work provides a foundation for adaptive FEC strategies in future DVB T2 systems, enabling broadcasters to deliver reliable high-definition content even under challenging channel conditions.

This paper studies a hybrid automatic repeat and request (HARQ) mechanism for multicast/broadcast services in 5G New Radio (NR) systems. HARQ is widely used in unicast transmission to improve reliability and resource efficiency under the fading channel. However, for multicast/broadcast, it is difficult to apply conventional HARQ technology because the probability of retransmission becomes high as the number of receiver increases. In this paper, we propose a novel and efficient retransmission scheme, called outer code- based HARQ. After the initial transmission of a given data packet for multicast/broadcast, each receiver sends feedback information on how many code blocks (CBs) are broken instead of which CBs are broken. Then, for retransmission of the data, the transmitter generates parity CBs by using outer code such as Reed- Solomon (RS) or Raptor code and transmits the parity CBs after applying inner code such as low density parity check (LDPC) code. Numerical results show that the proposed scheme outperforms the conventional HARQ schemes, reducing more than 50% of retransmissions.

In contrast to classical signature schemes, such as RSA or ECDSA signatures, the lattice-based signature scheme ring-TESLA is expected to be resistant even against quantum adversaries. Due to a recent key recovery from a lattice-based implementation, it becomes clear that cache side channels are a serious threat for lattice-based implementations. In this article, we analyze an existing implementation of ring-TESLA against cache side channels. To reduce the effort for manual code inspection, we selectively employ automated program analysis. The leakage bounds we compute with program analysis are sound overapproximations of cache-side-channel leakage. We detect four cache-side-channel vulnerabilities in the implementation of ring-TESLA. Since two vulnerabilities occur in implementations of techniques common to lattice-based schemes, they are also interesting beyond ring-TESLA. Finally, we show how the detected vulnerabilities can be mitigated effectively.

MLAS: Multiple level authentication scheme for VANETs

Proxy signature schemes based on factoring

Parallel combinatory multicarrier (PCMC) modulation is a generalisation of the legacy multicarrier frequency shift keying (FSK) scheme, where for each group of M subcarriers, more than one (say L) subcarriers are chosen for simultaneous transmission. The PCMC scheme provides an effective way to increase the spectral efficiency while maintaining non-coherent detection at the receiver. This study provides an in-depth study of the PCMC scheme with emphasis on how to couple with binary or non-binary channel coding. One favourable system configuration is identified, having parameters (L,M) = (4,8), which increases the spectral efficiency by 50% relative to the most efficient FSK scheme from the FSK family. Coupled with non-binary low-density parity-check (LDPC) coding over the Galois field GF(64), the PCMC scheme with (L,M) = (4,8) is shown to have robust performance in multipath fading channels.