Adaptive Chosen Message Attack Research Articles

IPCAS: An improved conditional privacy-preserving certificateless aggregate signature scheme without bilinear pairing for VANETs

Recently, Gong et al. proposed a Certificateless Aggregate Signature (CLAS) scheme (shorted by PCAS) with conditional privacy-preserving without bilinear pairing for Vehicular Ad-hoc Networks (VANETs). Unfortunately, after analyzing security, the PCAS scheme fails to satisfy the necessary unlinkability in VANETs and is vulnerable to the public key replacement forgery attack of the Type-I adversary. Subsequently, this article analyses the causes of these two security issues in detail and proposes an improved CLAS scheme for VANETs (called IPCAS). Through security analysis, this article proves that the IPCAS is existentially unforgeable under the adaptive chosen message attacks against Type-I and Type-II adversaries in the random oracle model, and satisfies the necessary security and privacy requirements in VANETs, including unlinkability. Finally, the performance analysis results show that compared to PCAS for single message and n aggregate messages (n=1000), the computational overhead of IPCAS is reduced by 20.01% and 49.08% respectively, and the communication overhead is reduced by 18.75% and 28.14% respectively. Therefore, IPCAS not only makes up for the security vulnerabilities of PCAS but also has better performance.

A Certificateless Linearly Homomorphic Signature Scheme Based on Lattice for Network Coding

Abstract Homomorphic signature is an extremely important public key authentication technique for network coding to defend against pollution attacks. However, there are many problems with previous homomorphic signature schemes which require key escrow, cannot resist malicious key generation center (KGC), and are insecure in the post-quantum era. Therefore, we propose a lattice-based certificateless linearly homomorphic signature scheme. In our scheme, certificateless structure can avoid key escrow and malicious KGC. The lattice structure ensures that our scheme is secure in the post-quantum era. The bimodal Gaussian distribution is used to improve the security and the efficiency. Compared with the previous schemes, our scheme has smaller storage space (no key escrow), can avoid malicious KGC, is more secure in the post-quantum era, and has higher signature efficiency. At the same time, our scheme is more suitable for network coding. Finally, under random oracle model, we proved that our scheme is weakly context hiding and existentially unforgeable against adaptive chosen message attacks against external attackers and the internal KGC.

A Lightweight Identity-Based Network Coding Scheme for Internet of Medical Things

Network coding is a potent technique extensively utilized in decentralized Internet of Things (IoT) systems, including the Internet of Medical Things (IoMT). Nevertheless, the inherent packet-mixing characteristics of network coding expose data transmission to pollution attacks, potentially compromising the integrity of original files. The homomorphic signature scheme serves as a robust cryptographic tool that can bolster network coding’s resilience against such attacks. However, current schemes are computationally intensive for signature verification, making them impractical for IoMT environments. In this study, we propose a lightweight identity-based network coding scheme (IBNS) that minimizes computational overhead during the signing and verification processes. This scheme has been demonstrated to be secure against adaptive chosen-message attacks and is well-suited for IoMT applications. Furthermore, we assess the performance of our IBNS through both theoretical and experimental analyses. Simulation outcomes confirm that our scheme outperforms previous ones in terms of practicality and efficiency.

Practical NTRU Signcryption in the Standard Model.

Based on the NTRU trapdoor used in NIST's Falcon, a signcryption scheme following the sign-then-encrypt paradigm is constructed. The existing partitioning technique based on Waters hash over the lattice can not complete the security reduction in the standard model for the signature part due to the "partiality" of the pre-image generated with the NTRU trapdoor. To address this, a variant of Waters hash over small integers is proposed and, the probability of the successful reduction is analyzed. The resulting signcryption achieves existential unforgeability under the adaptive chosen-message attacks. By utilizing the uniqueness of the secret and the noise in an NTRU instance, the tag used in encryption is eliminated. Furthermore, a method to construct tamper-sensitive lattice public key encryption is proposed. This approach implants the ciphertext-sensitive information into the lattice public key encryption and binds it to the encrypted information. The malleability to the public key ciphertext triggers the change of the message-signature pair so that the IND-CCA2 security of the entire ciphertext can be guaranteed by the signature for the message. Thanks to the rational design and the efficiency of the NTRU trapdoor, the computational overhead of the proposed scheme is reduced significantly compared to the existing lattice-based signcryption scheme, reaching orders of magnitude improvement in efficiency. The experiment shows that the proposed scheme is efficient.

Secure Equality Test Technique Using Identity-Based Signcryption for Telemedicine Systems

For telemedicine, Wireless Body Area Network (WBAN) offers enormous benefits where a patient can be remotely monitored without compromising the mobility of remote treatments. With the advent of high capacity and reliable wireless networks, WBANs are used in several remote monitoring systems, limiting the COVID-19 spread. The sensitivity of telemedicine applications mandates confidentiality and privacy requirements. In this paper, we propose a secure WBAN-19 telemedicine system to overcome the pervasiveness of contagious deceases utilizing a novel aggregate identity-based signcryption scheme with an equality test feature. We demonstrate a security analysis regarding indistinguishable adaptive chosen-ciphertext attack (IND-CCA2), one-way security against adaptive chosen-ciphertext attack (OW-CCA2), and unforgeability against adaptive chosen-message attack (EUF-CMA) under the random oracle model. The security analysis of the scheme is followed by complexity evaluations where the computation cost and communication overhead are measured. The evaluation demonstrates that the proposed model is efficient and applicable in telemedicine systems with high-performance capacities.

A Security-Enhanced Pairing-Free Certificateless Aggregate Signature for Vehicular Ad-Hoc Networks

As self-organizing, highly heterogeneous and multi-interactive networks, vehicular ad-hoc networks (VANETs) are rapidly improving the efficiency of modern traffic. This promising technology is significant for supporting current intelligent transportation by cooperative data sharing and processing. Considering requirements for secure interactions and the limitation of resources in VANETs, protecting data authenticity while enhancing computational efficiency has become the main challenge. A certificateless aggregate signature (CLAS) can not only ensure data security, but also reduce communication costs, which is suitable for a resource-constrained environment. However, most existing CLAS schemes either own serious security vulnerabilities or result in tremendous computational overhead. In this article, we propose an efficient, privacy-preserving, and pairing-free CLAS scheme with enhanced security. We prove that it is existentially unforgeable against adaptive chosen message attacks in the random oracle model. Performance evaluation illustrates that our proposed scheme is more appropriate to the VANETs scenario.

EBiBa: A Post-Quantum Hash-Based Signature With Small Signature Size in the Continuous Communication of Large-Scale Data

Abstract We present eBiBa (enhanced BiBa), a hash-based signature scheme with the smallest possible signature size, while ensuring high feasibility and security in a specific application model. Our scheme is tailored to address the communication requirement of a large-scale public data stream continuously disseminated between two participants while ensuring data source and data integrity authentication. To achieve these goals, firstly, we optimized the classical hash tree mode into a hybrid mode to efficiently perform public key authentication and eliminate the need for an authenticated channel to transmit large amounts of data, unlike the initial BiBa-based broadcast authentication protocol. Secondly, we employed a specific tweakable hash chain function to digest a batch of messages, reducing the required conditions for post-quantum existential unforgeability under adaptive chosen message attack (EUCMA) of eBiBa to a second-pre-image-resistance-like property instead of collision resistance. This results in reduced pre-computation in both key and signature generations. Thirdly, we utilized a forward-secure pseudorandom function to achieve forward-secure of the proposed scheme. Finally, we minimize the signature size through a series of procedures. Firstly, we select BiBa few-time signature as the underlying signature scheme since it is currently the few-time hash-based signature with the smallest signature size that we are aware of; in addition, the hybrid approach we employed can also significantly reduce the signature size compared to using a hash tree solely; for the hash tree structure, we design a specific authentication path in combination with the related communication model to further minimize the signature size; finally, we optimize the authentication approach to achieve the minimum signature size in a single transmission. Our construction minimizes the signature size in the aforementioned model, achieving a compression rate of 0.017 to 0.828 based on distinct values of parameters, as compared to XMSS-256. We also demonstrated that eBiBa can achieve post-quantum forward-secure and EUCMA security.

An Efficient Cross-Layer Authentication Scheme for Secure Communication in Vehicular Ad-Hoc Networks

Intelligent transportation systems contribute to improved traffic safety by facilitating real-time communication between vehicles and infrastructures. In this context, message authentication is crucial to safeguard vehicular ad-hoc networks (VANETs) from malicious attacks. The current state-of-the-art for authentication in VANETs relies on conventional cryptographic primitives, introducing significant computation and communication overheads. This paper presents a cross-layer authentication scheme for vehicular communication, incorporating the short-term reciprocal features of the wireless channel for re-authenticating the corresponding terminal, reducing the overall complexity and computation and communication overheads. The proposed scheme comprises four steps: S1. Upper-layer authentication is used to determine the legitimacy of the corresponding terminal at the first time slot; S2. Upon the verification result, a location-dependent shared key with a minimum number of mismatched bits is extracted between both terminals; S3. Using the extracted key and under binary hypothesis testing, a PHY challenge-response algorithm for multicarrier communication is proposed for re-authentication; S4. In the case of false detection, the key extraction step (S2) is re-executed after adapting the quantisation levels at different conditions of channel non-reciprocity based on the feedback from the re-authentication step (S3). Simulation results show the effectiveness of the proposed scheme even at small signal-to-noise ratios. In addition, the immunity of the proposed scheme is proved against active and passive attacks, including signatures' unforgeability against adaptive chosen message attacks in the random oracle model. Finally, a comprehensive comparison in terms of computation and communication overheads demonstrates the superiority of the proposed scheme over its best rivals.

Improved Security of a Pairing-Free Certificateless Aggregate Signature in Healthcare Wireless Medical Sensor Networks

Recently, Zhan et al. presented a pairing-free certificateless aggregation signature scheme (ZH-CLAS) to address security issues in healthcare wireless medical sensor networks (HWMSNs), and proved that their scheme is secure against adaptive chosen message attacks. In this article, we analyze the security of the ZH-CLAS scheme by utilizing two types of concrete attacks. Unfortunately, we demonstrate that their scheme cannot withstand public key replacement attacks and is not secure against coalition attacks from malicious sensor nodes. To solve these security challenges, we further improve the security of the ZH-CLAS scheme. Our enhanced scheme has a fixed-length aggregate signature, which efficiently minimizes the transmission bandwidth. Additionally, our scheme outperforms related pairing-free CLAS schemes in terms of security and communication performance.

Efficient and Secure Certificateless Signcryption Without Pairing for Edge Computing-Based Internet of Vehicles

The emergence of the vehicular ad-hoc network (VANETs) could meet the need for an efficient and safe transportation. Vehicles wirelessly interact with nearby road-side units (RSUs) and send the data to the cloud servers (CS), but this approach has limitations (i.e. network congestion and privacy leakage). Edge computing can effectively solve problems of network congestion, feedback delay and privacy leakage during transmission caused by CS. Thus, this paper proposes a certificateless aggregate signcryption with online/offline encryption (CLOASC) based on edge computing (EDC). Correspondingly, certificateless signcryption (CLSC), online/offline encryption (OOE) and aggregate signcryption technology solve the key escrow problem, shorten the encryption time and realize the quick verification of multiple users, respectively. Furthermore, it is worth mentioning that the scheme we propose does not have any bilinear pairings or scalar multiplications in the online encryption stage, which greatly reduces the computational cost in the online stage. In the random oracle model, our scheme was proved to be existential unforgeability under adaptive chosen message attacks (EUF-ACM) and adaptive indistinguishability under chosen-ciphertext attack (IND-CCA2) security. Simulation results show that our scheme is computationally and communication based lightweight as compared to the related.

DPB-MA: Low-Latency Message Authentication Scheme Based on Distributed Verification and Priority in Vehicular Ad Hoc Network

Vehicular ad hoc networks (VANETs) serve as crucial means to ensure safe transportation systems and enhance driving convenience. Ensuring authentication between vehicles and units is the most essential line of defense for VANETs systems. Various schemes of message authentication are put forward to realize safe communication in VANETs. However, these schemes mainly pay attention to privacy and security issues, and are not fit for high-density traffic environments where many messages should be verified by a roadside unit (RSU). At present, achieving the low-latency authentication under the security and privacy of messages remains a critical requirement and challenge. For addressing this problem, this study puts forward a novel low-latency message authentication scheme based on the distributed authentication and message priority (DPB-MA), which can minimize message verification latency through cooperation between the RSU and cooperative vehicles (CVs). In addition, a message priority strategy has been designed to ensure that urgent messages are preferentially verified. According to the security proof with tight reduction, the DPB-MA is existentially unforgeable against adaptive chosen message attack (EU-CMA) in the random oracle model (ROM). Furthermore, our DPB-MA achieves full message aggregation, which also greatly optimizes the communication overhead and authentication efficiency. Performance analysis indicates that our scheme works well in high-density traffic scenarios and is more suitable for securing emergency messages with ultra-low latency requirements.

A Security-Enhanced and Privacy-Preserving Certificateless Aggregate Signcryption Scheme-Based Artificial Neural Network in Wireless Medical Sensor Network

With the recent advances in mobile sensing and beyond-5G technologies, wireless medical sensor networks (WMSNs) have become an emerging hot topic in smart healthcare. Under the condition of limited resources of medical sensor nodes (MSNs), ensuring the accuracy and integrity of a large number of patients’ medical data is a crux for security and data privacy issues. In order to overcome the limitations of medical sensors in communication and computing capabilities, and to achieve privacy in WMSN, we propose a low complexity certificateless aggregate signcryption (CL-ASC) scheme-based artificial neural network (NN) for safely achieving authentication and unforgeability of medical nodes. We use an adaptive sigma filter for denoising, adopt Levenshtein entropy for encoding, and design cryptographic protocol for signcrypting in the hidden layer of deep feedforward artificial NN (DFANN). The CL-ASC can authenticate all sensing bioinformation at once in a privacy-preserving way. Given the challenge of applying a discrete logarithm and computational Diffie-Hellman problems based on an elliptic curve, the proposed scheme satisfies the indistinguishability against chosen-ciphertext attacks (IND-CCA) and the adaptive chosen message attack (UF-CMA) security properties under the random oracle model (ROM). Finally, the benchmark evaluation shows that ours is ahead of similar state-of-the-art schemes, due to its low complexity and higher computational efficiency. Researchers interested in the provable security protocol design and framework of NNs can gain useful insights from this research and identify future cross domain of cybersecurity and NNs research directions based on the proposed scheme herein.

PCAS: Cryptanalysis and improvement of pairing-free certificateless aggregate signature scheme with conditional privacy-preserving for VANETs

Certificateless aggregate signature (CLAS) is an effective approach for the multiple authentications in multi-users and multi-information environments like the vehicular ad hoc networks (VANETs), which can address the certificate management issue in the traditional public key cryptography (PKC) and solve the key escrow problem in identity-based cryptography (IBC). In recent years, a new CLAS mechanism (LICLAS) is presented for the authentication of sensors in healthcare wireless medical sensor networks (HWMSNs). In this paper, we make an analysis and prove that LICLAS is not able to against forgery attacks. Thus, we present an improved CLAS scheme (PCAS) for vehicle authentication in VANETs, which satisfies the privacy and security requirements. PCAS constructs the signature algorithm based on Elliptic Curve Cryptography (ECC) to avoid bilinear pairing and Map-to-Hash function operations. In order to further improve security and efficiency of PCAS, the vehicle key generation and signature algorithm is revised. The pseudonym mechanism is also adopted to achieve conditional privacy preservation. Besides, PCAS allows to execute a batch verification of messages, where RSUs may verify the aggregated signatures from vehicles to reduce time overhead. Under the assumption that the elliptic curve discrete logarithm problem (ECDLP) is hard, PCAS is proved to be existentially unforgeable against adaptive chosen message attacks in the random oracle model. Through the performance analysis, under the same time complexity, PCAS is shown to more effective. Compared with LICLAS, for a single message and 2000 messages, the transmission overhead of PCAS is reduced by 25% and 25% respectively, and the computation overhead is reduced by 16.56% and 25.34% respectively.

Authenticated Key Exchange Protocol in the Standard Model under Weaker Assumptions

A two-party authenticated key exchange (AKE) protocol allows each of the two parties to share a common secret key over insecure channels, even in the presence of active adversaries who can actively control and modify the exchanged messages. To capture the malicious behaviors of the adversaries, there have been many efforts to define security models. Amongst them, the extended Canetti–Krawczyk (eCK) security model is considered one of the strongest security models and has been widely adopted. In this paper, we present a simple construction of a pairing-based eCK-secure AKE protocol in the standard model. Our protocol can be instantiated with a suitable signature scheme (i.e., an existentially unforgeable signature scheme against adaptive chosen message attacks). The underlying assumptions of our construction are the decisional bilinear Diffie–Hellman assumption and the existence of a pseudorandom function. Note that the previous eCK-secure protocol constructions either relied on random oracles for their security or used somewhat strong assumptions, such as the existence of strong-pseudorandom functions, target collision-resistant functions, etc., while our protocol construction uses fewer and more-standard assumptions in the standard model. Furthermore, preserving the same security argument, our protocol can be instantiated with any appropriate signature scheme that comes in the future with better efficiency.

A Linear Homomorphic Proxy Signature Scheme Based on Blockchain for Internet of Things

The mushroom growth of IoT has been accompanied by the generation of massive amounts of data. Subject to the limited storage and computing capabilities of most IoT devices, a growing number of institutions and organizations outsource their data computing tasks to cloud servers to obtain efficient and accurate computation while avoiding the cost of local data computing. One of the most important challenges facing outsourcing computing is how to ensure the correctness of computation results. Linearly homomorphic proxy signature (LHPS) is a desirable solution to ensure the reliability of outsourcing computing in the case of authorized signing right. Blockchain has the characteristics of tamper-proof and traceability, and is a new technology to solve data security. However, as far as we know, constructions of LHPS have been few and far between. In addition, the existing LHPS scheme does not focus on homomorphic unforgeability and does not use blockchain technology. Herein, we improve the security model of the LHPS scheme, and the usual existential forgery and homomorphic existential forgery of two types of adversaries are considered. Under the new model, we present a blockchain-based LHPS scheme. The security analysis shows that under the adaptive chosen message attack, the unforgeability of the proposed scheme can be reduced to the CDH hard assumption, while achieving the usual and homomorphic existential unforgeability. Moreover, compared with the previous LHPS scheme, the performance analysis shows that our scheme has the same key size and comparable computational overhead, but has higher security.

Certificateless threshold signature from lattice

Threshold signature has been widely used in electronic wills, electronic elections, cloud computing, secure multi-party computation and other fields. Until now, certificateless threshold signature schemes are all based on traditional mathematic theory, so they cannot resist quantum computing attacks. In view of this, we combine the advantages of lattice-based cryptosystem and certificateless cryptosystem to construct a certificateless threshold signature from lattice (LCLTS) that is efficient and resistant to quantum algorithm attacks. LCLTS has the threshold characteristics and can resist the quantum computing attacks, and the analysis shows that it is unforgeable against the adaptive Chosen-Message Attacks (UF-CMA) with the difficulty of Inhomogeneous Small Integer Solution (ISIS) problem. In addition, LCLTS solves the problems of the certificate management through key escrow.

A certificateless ring signature scheme based on lattice

SummaryFor the problems that ring signature needs key escrow, has some security risks, and cannot avoid malicious key generation center (KGC) in the post‐quantum era, we design a certificateless ring signature scheme based on lattice (L‐CRSS). In our scheme, the bimodal Gaussian distribution is used to improve the security and efficiency. Compared with the previous ring signature scheme based on lattice, our design does not need key escrow, does not disclose the signer's identity, can avoid malicious KGC, achieves the constant signature size, and has higher security and efficiency in the post‐quantum era. Finally, under random oracle model (ROM), we prove that our scheme is anonymous against the full‐key exposure, and existentially unforgeable against adaptive chosen message attacks (EUF‐CMA).

A Lattice-Based Redactable Signature Scheme using Cryptographic Accumulators for Trees

Abstract Redactable signatures allow the signature holder to remove admissible data blocks in the signed data while generating valid signatures about different redacted data without communicating with the primary signer. Now, this sort of signature has attracted widespread attention due to its many application scenarios such as electronic medical records, smart grids and XML files. However, there are rarely redactable signature schemes that can resist quantum attacks so far. In the wake of quantum calculation era, it is essential to blossom more quantum-resistant redactable signatures for different data structures. Moreover, it is popular to use accumulators to design redactable signature schemes. Unfortunately, the existing accumulators do not support tree data structures. Therefore, this paper first gives the definition of accumulator schemes for trees, and designs a lattice-based accumulator scheme for trees. Our accumulator scheme features shorter accumulator values and a faster witness generation algorithm than existing lattice trapdoor accumulators. Second, this paper resorts to approximate trapdoors and the preimage sampleable technique, and presents a lattice-based redactable signature scheme for trees using our accumulator scheme. Meanwhile, this scheme fulfills unforgeability, transparency and privacy under adaptive chosen-message attacks. Furthermore, the experiment results show that the redactable signature scheme meets actual revision requirements well.

Certificateless multi-source signcryption with lattice

Network coding can improve network transmission performance and reduce data transmission delay. However, the nodes in network are vulnerable to pollution attacks. Previous network coding schemes are based on difficult problems in number theory and cannot resist the quantum computing attacks. Hence, certificateless multi-source signcryption with lattice (LCL-MSSC) is devised for network coding, it uses common public key to verify the combination ciphertext from different source node users. Based on learning with errors and inhomogeneous small integer solution problems, LCL-MSSC is unforgeable under the adaptive chosen-message attacks and indistinguishable under the adaptive chosen-ciphertext attacks; in addition, it can resist the pollution attacks and quantum computing attacks. Efficient LCL-MSSC has broad application prospect in UAV wireless communication network, mobile wireless network, wireless sensor network or cyberspace security.

Elliptic curve threshold signature scheme for blockchain

Smart contract execution requires the triggering condition. Triggering condition of smart contract is the information outside the blockchain, and thus an oracle is required to provide the data services. For the security of user funds in on-chain aggregation model, each oracle must pay the gas fees to transmit off-chain data to the blockchain and trigger the smart contract, but this way easily causes the network congestion. In view of this, we propose an elliptic curve threshold signature scheme for blockchain (BC-ECTSS) to overcome the above issue. In the random oracle (RO) model, we detailedly show BC-ECTSS satisfies the existential unforgeability against the adaptive chosen-message attacks; in addition, it has the anonymity and its computation cost is relatively low.