Post-quantum Security Research Articles

A fully secure lattice-based signcryption with designated equality test in standard model

In hospital information systems, large volumes of electronic diagnostic records (EDRs) take up most of the storage space. While cloud server providers can reduce the local storage burden on hospitals and provide data-sharing services, the potential threat of sensitive data leakage and non-traceability of diagnoses prevents hospitals from uploading patients' diagnostic records to remote cloud servers directly. Therefore, to address security and traceability issues, we propose a new construction of post-quantum secure signcryption scheme with a designated equality test based on lattices (LB-SCDET) in this paper. Our LB-SCDET scheme allows a designated tester to perform equality tests on signcrypt-ciphertexts of EDRs without leaking what the EDRs actually are. Compared to the recent LB-SCET scheme proposed by Le et al., our LB-SCDET scheme implements a designated mechanism and is secure against offline message recovery attacks (OMRA). The comparison shows that our scheme enjoys a higher level of security, albeit the ciphertext size is slightly larger. Finally, we prove the scheme to be secure under the hardness of the Learning-with-Errors problem and unidirectionality of the Short-Integer-Solution problem. To be of independent interest, we show that the LB-SCET scheme fails to achieve the claimed IND-CCA security.

Deep learning-based biometric cryptographic key generation with post-quantum security

Deep learning-based biometric cryptographic key generation with post-quantum security

A lattice-based designated-server public-key authenticated encryption with keyword search

Public-key Encryption with Keyword Search (PEKS) provides an efficient way to search on encrypted cloud data. However, it cannot resist against off-line Inside Keyword Guessing Attacks (IKGA). To alleviate this issue, Huang and Li proposed the Public-key Authenticated Encryption with Keyword Search (PAEKS), which the keyword is also authenticated. However, they do not provide post-quantum security promises. In this paper, we propose the first lattice-based designated-server PAEKS (dPAEKS). We formally define dPAEKS and its security models, and propose a lattice-based construction. It is quantum-resistant under the assumption of learning with errors and the sender authenticated the keyword so it can resist IKGA. Furthermore, we strengthen the security requirement, so that only the designated tester can search the ciphertext. Finally, we compare our scheme with some related schemes to demonstrate its efficiency.

Development of quantum-enhanced authenticated key agreement protocol for autonomous vehicles

Autonomous vehicle (AV) technology for self-driving has emerged as a promising solution to alleviate traffic congestion, reduce accidents, and optimize road capacity and fuel consumption. However, these sensors are vulnerable, making AVs susceptible to cyber threats. Consequently, security becomes an indispensable and integral facet of AV architecture. One such challenge is establishing a secure session key between the sensor device and other entities to ensure secure and authorized communication. While some existing schemes support pre-quantum era secure session key establishment within AV systems, post-quantum security's a discernible gap.This paper introduces an innovative quantum secure and highly efficient authentication and key agreement (AKA) scheme. We propose a cloud-centric three-factor authentication and key agreement system based on Ring Learning With Errors (RLWE) to provide robust authentication for both cloud and AVs. Furthermore, we have devised two distinct session keys within our authentication mechanism: one for secure remote control between users and AVs, and the other for ensuring enhanced privacy when accessing cloud-stored data via the cloud server. The efficacy of our proposed design is substantiated through a comprehensive comparative study that includes performance evaluation. Our proposed scheme has better efficiency than existing schemes and is suitable for the post-quantum era.

Post-Quantum Security: Opportunities and Challenges

Cryptography is very essential in our daily life, not only for confidentiality of information, but also for information integrity verification, non-repudiation, authentication, and other aspects. In modern society, cryptography is widely used; everything from personal life to national security is inseparable from it. With the emergence of quantum computing, traditional encryption methods are at risk of being cracked. People are beginning to explore methods for defending against quantum computer attacks. Among the methods currently developed, quantum key distribution is a technology that uses the principles of quantum mechanics to distribute keys. Post-quantum encryption algorithms are encryption methods that rely on mathematical challenges that quantum computers cannot solve quickly to ensure security. In this study, an integrated review of post-quantum encryption algorithms is conducted from the perspective of traditional cryptography. First, the concept and development background of post-quantum encryption are introduced. Then, the post-quantum encryption algorithm Kyber is studied. Finally, the achievements, difficulties and outstanding problems in this emerging field are summarized, and some predictions for the future are made.

A module lattice based construction of post quantum secure blockchain architecture

AbstractThe Fiat–Shamir with Aborts paradigm of Lyubashevsky introduced efficient lattice based signatures. A lattice‐based signature is used to design post quantum secure blockchain architecture. But, a blockchain is always consisting of multiple nodes, and then we need an efficient aggregate signature to verify nodes in one‐step. We have designed a blockchain using module lattices. Blockchain security relies upon two assumptions, (1) module learning with errors and (2) module short integer solution. The proposed design ensures security against quantum attacks. The design is simulated in ns‐3 to capture latency and throughput, respectively.

A Privacy-Preserving State Estimation Scheme for Smart Grids

With the appearance of electric energy market deregulation, there exists a growing concern over the potential privacy leakage of commercial data among competing power companies where data sharing is essential in the applications such as smart grid state estimation. Most of the existing solutions are either perturbation-based or conventional cryptography-based where a trusted central 3rd party would often be required. This paper proposes privacy-preserving state estimation protocols for DC and AC models. The proposed idea is to distribute the overall task of the system state estimation into sub-tasks which can be performed by local sub-grid operators with their private data. A masking method is designed inside a homomorphic encryption scheme which is then used to ensure both the input and output data privacy during the collaboration process among individual sub-task players. Security is achieved via the computationally indistinguishable post-quantum security guaranteed by a levelled homomorphic encryption scheme over real numbers and the differential privacy of the output estimated states provided by the Laplace mechanism perturbation integrated into the masking linear transformation. Simulation results are presented to demonstrate the validity of our proposed privacy-preserving system state estimation protocols.

Post-quantum secure group signature with verifier local revocation and backward unlinkability

Group signature supports users to generate signatures on behalf of the group. Verifier local revocation (VLR) is an important method to revoke a misbehaving user in group signature, which has attracted many researchers’ attention. However, the existing lattice-based group signature schemes with VLR either achieve only selfless anonymity, have revocation list of size linear with the number of revoked users, or suffer from the issue that signatures generated by revoked users could easily be linked by an adversary. Additionally, the development of quantum computing technology threatens the security of traditional cryptosystems. Therefore, in this paper we propose a new lattice-based group signature scheme, which makes use of the complete tree technique to combine the timestamp with VLR. It enjoys post-quantum security and satisfies almost full anonymity and traceability if the LWE and SIS problems are hard. Compared with previous schemes, our scheme achieves backward unlinkability additionally. Thanks to the revocation token update mechanism, a revocation token for time period t could not be connected with signatures generated in period t+1. Furthermore, the revocation list in our scheme only stores the tokens of users who have been revoked before the expiry, reducing the revocation list size effectively.

Research on Quantum-Attack-Resistant Strong Forward-Secure Signature Schemes.

The security of digital signatures depends significantly on the signature key. Therefore, to reduce the impact of leaked keys upon existing signatures and subsequent ones, a digital signature scheme with strong forward security could be an effective solution. Most existing strong forward-secure digital signature schemes rely on traditional cryptosystems, which cannot effectively resist quantum attacks. By introducing lattice-based delegation technology into the key-iteration process, a two-direction and lattice-based key-iteration algorithm with strong forward security is proposed. In the proposed algorithm, a unique key pair is assigned to the signer in every period. Based on the proposed algorithm, a strong forward-secure signature scheme is further put forward, which achieves resistance to quantum attacks. Performance analysis shows that under the security assumption of the SIS problem on the lattice, the proposed strong forward-secure signature scheme is existentially unforgeable under the random oracle model. Ultimately, based on the proposed strong forward-secure signature scheme, a remote identity-authentication scheme that is resistant to quantum attacks is proposed, ensuring post-quantum security in the user-authentication process.

Post-Quantum Secure Identity-Based Proxy Blind Signature Scheme on a Lattice.

Blind signatures have been widely applied when privacy preserving is required, and the delegation of blind signature rights and a proxy blind signature (Proxy-BS) become necessary when the signer cannot sign. Existing Proxy-BS schemes are based on traditional cryptographically hard problems, and they cannot resist quantum attacks. Moreover, most current Proxy-BS schemes depend on public key infrastructure (PKI), which leads to high certificate storage and management overhead. To simplify key management and resist quantum attacks, we propose a post-quantum secure identity-based proxy blind signature (ID-Proxy-BS) scheme on a lattice using a matrix cascade technique and lattice cryptosystem. Under the random oracle model (ROM), the security of the proposed scheme is proved. Security shows that the proposed scheme assures security against quantum attacks and satisfies the correctness, blindness, and unforgeability. In addition, we apply the ID-Proxy-BS scheme on a lattice to e-voting and propose a quantum-resistant proxy e-voting system, which is resistant to quantum attacks and achieves the efficiency of e-voting.

Post-quantum secure authenticated key agreement protocol for wireless sensor networks

Post-quantum secure authenticated key agreement protocol for wireless sensor networks

On post-quantum security of symmetric cryptosystems

On post-quantum security of symmetric cryptosystems

An Efficient Identity-Based Encryption With Equality Test in Cloud Computing

Identity-based encryption with equality test (IBEET) provides a feasible way for cloud server partitioning or searching on ciphertexts in the cloud. In that case, the server can judge if two different ciphertexts encrypt the same plaintexts or not. In response to threats posed by quantum computers, lattice-based IBEET schemes have been proposed to make cloud service post-quantum secure. However, those schemes are inefficient and can hardly meet the needs of resource-constrained devices. In this paper, an efficient post-quantum IBEET scheme is introduced, which achieves testability by embedding the hash value of plaintext into testing trapdoor instead of encrypting it directly and doubling the size of ciphertext. We also prove that, with the Learning With Errors (LWE) problem assumption, the new scheme is one-way secure against selective identity and chosen ciphertext attacks (OW-sID-CCA) in quantum secure model. Furthermore, we evaluate the performance of the new construction and demonstrate its efficiency by showing that it only costs about half storage comparing with other lattice-based IBEET schemes. The execution time of encryption and decryption phrases in the new scheme reduce by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$50\%$</tex-math></inline-formula> , while the computational cost in test algorithm keeps the same. Therefore, the new proposed IBEET is much more practical for working in post-quantum cloud computing scenarios.

Enabling FrodoKEM on Embedded Devices

FrodoKEM is a lattice-based Key Encapsulation Mechanism (KEM) based on unstructured lattices. From a security point of view this makes it a conservative option to achieve post-quantum security, hence why it is favored by several European authorities (e.g., German BSI and French ANSSI). Relying on unstructured instead of structured lattices (e.g., CRYSTALS-Kyber) comes at the cost of additional memory usage, which is particularly critical for embedded security applications such as smart cards. For example, prior FrodoKEM-640 implementations (using AES) on Cortex-M4 require more than 80 kB of stack making it impossible to run on some embedded systems. In this work, we explore several stack reduction strategies and the resulting time versus memory trade-offs. Concretely, we reduce the stack consumption of FrodoKEM by a factor 2–3x compared to the smallest known implementations with almost no impact on performance. We also present various time-memory trade-offs going as low as 8 kB for all AES parameter sets, and below 4 kB for FrodoKEM-640. By introducing a minor tweak to the FrodoKEM specifications, we additionally reduce the stack consumption down to 8 kB for all the SHAKE versions. As a result, this work enables FrodoKEM on more resource constrained embedded systems.

Isoga: An Isogeny-Based Quantum-Resist Searchable Encryption Scheme Against Keyword Guessing Attacks

Driven by cloud computing technologies, public-key encryption with keyword search (PEKS) is becoming a common practice from aspects of the Industrial Internet of Things, smart healthcare, vehicular social networks, and so on. However, a dozen years of PEKS development is accompanied by some security and privacy issues in the encrypted data search and access processes. The keyword guessing attack is a typical user privacy threat model, that is, an adversary could guess the user&#x2019;s retrieval keyword given a search trapdoor. On the other hand, the emergence of quantum computers make traditional PEKS schemes no longer secure. Although scholars put forward some postquantum secure PEKS schemes, these schemes are based on lattice cryptography with a larger key size. To the best of our knowledge, there is no quantum-resist PEKS scheme established on elliptic curve cryptography. This article utilizes PEKS with designated tester primitive and quantum resistance of isogeny. Then, we put forward a postquantum searchable encryption scheme named Isoga, which fights against keyword guessing attacks. We prove Isoga&#x2019;s searchable ciphertext security and trapdoor indistinguishability under isogeny-related difficult assumptions. Performance evaluation indicates that the Isoga scheme is more practical in the quantum environment, considering seven schemes&#x2019; security properties, communication cost, and computing overload among.

Post-quantum secure recipient revocable broadcast encryption supporting anonymity

Post-quantum secure recipient revocable broadcast encryption supporting anonymity

Secure Biomedical Document Protection Framework to Ensure Privacy Through Blockchain.

In the recent health care era, biomedical documents play a crucial role, and they contain much evidence-based documentation associated with many stakeholders data. Protecting those confidential research documents is more difficult and effective, and a significant process in the medical-based research domain. Those bio-documentation related to health care and other relevant community-valued data are suggested by medical professionals and processed. Many traditional security mechanisms such as akteonline and Health Insurance Portability and Accountability Act (HIPAA) are used to protect the biomedical documents as they consider the problem of non-repudiation and data integrity related to the retrieval and storage of documents. Thus, there is a need for a comprehensive framework that improves protection in terms of cost and response time related to biomedical documents. In this research work, blockchain-based biomedical document protection framework (BBDPF) is proposed, which includes blockchain-based biomedical data protection (BBDP) and blockchain-based biomedical data retrieval (BBDR) algorithms. BBDP and BBDR algorithms provide consistency on the data to prevent data modification and interception of confidential data with proper data validation. Both the algorithms have strong cryptographic mechanisms to withstand post-quantum security risks, ensuring the integrity of biomedical document retrieval and non-deny of data retrieval transactions. In the performance analysis, Ethereum blockchain infrastructure is deployed BBDPF and smart contracts using Solidity language. In the performance analysis, request time and searching time are determined based on the number of request to ensure data integrity, non-repudiation, and smart contracts for the proposed hybrid model as it gets increased gradually. A modified prototype is built with a web-based interface to prove the concept and evaluate the proposed framework. The experimental results revealed that the proposed framework renders data integrity, non-repudiation, and support for smart contracts with Query Notary Service, MedRec, MedShare, and Medlock.

Privacy-Preserving Preselection for Protected Biometric Identification Using Public-Key Encryption With Keyword Search

The efficiency of biometric systems, in particular efficient and accurate biometric identification, is one of the most challenging open problems in biometrics today. Adding to that, biometric data are sensitive data deserving adequate protection. As a solution, this work proposes an efficient privacy-preserving reduction of the computational workload of biometric identification systems using public-key encryption with keyword search (PEKS). For long-term protection of the biometric data, fully homomorphic encryption is applied for template protection. As all applied cryptographic schemes are lattice-based, they also offer post-quantum security. Throughout the system, the recognition accuracy of the unprotected system is preserved. In an evaluation on a public face database, the computational workload of an identification search in the encrypted domain is reduced down to 8.4&#x0025; compared to an exhaustive search, achieving identification on 1062 subjects in 210 milliseconds. Based on these results, an identification search on 1 million subjects can be estimated at under 3 minutes using off-the-shelf hardware.

Post-quantum security on the Lai–Massey scheme

Post-quantum security on the Lai–Massey scheme

A Lightweight, Secure Big Data-Based Authentication and Key-Agreement Scheme for IoT with Revocability

With the rapid development of Internet of Things (IoT), designing a secure two-factor authentication scheme for IoT is becoming increasingly demanding. Two-factor protocols are deployed to achieve a higher security level than single-factor protocols. Given the resource constraints of IoT devices, other factors such as biometrics are ruled out as additional authentication factors due to their large overhead. Smart cards are also prone to side-channel attacks. Therefore, historical big data have gained interest recently as a novel authentication factor in IoT. In this paper, we show that existing big data-based schemes fail to achieve their claimed security properties such as perfect forward secrecy (PFS), key compromise impersonation (KCI) resilience, and server compromise impersonation (SCI) resilience. Assuming a real strong attacker rather than a weak one, we show that previous schemes not only fail to provide KCI and SCI but also do not provide real two-factor security and revocability and suffer inside attack. Then, we propose our novel scheme which can indeed provide real two-factor security, PFS, KCI, and inside attack resilience and revocability of the client. Furthermore, our performance analysis shows that our scheme has reduced modular exponentiation operation and multiplication for both the client and the server compared to Liu et al.’s scheme which reduces the execution time by one third for security levels of λ = 128 . Moreover, in order to cope with the potential threat of quantum computers, we suggest using lightweight XMSS signature schemes which provide the desired security properties with λ = 128 bit postquantum security. Finally, we prove the security of our proposed scheme formally using both the real-or-random model and the ProVerif analysis tool.