With the advancement in quantum computing technology, the number theory-based hard problems underlying traditional searchable encryption algorithms are now vulnerable to efficient quantum attacks. To address this challenge, this paper proposes Dilithium-PAEKS (Dilithium-Public Authenticated Encryption with Keyword Search), a searchable encryption scheme based on the post-quantum cryptographic algorithm CRYSTALS-Dilithium. By transforming the verification relationship of digital signatures into a matching relationship between trapdoors and ciphertexts, the scheme not only meets the functional requirements of searchable encryption but also demonstrates quantum resistance. The implementation enhances algorithm efficiency through keyword-based signatures and dynamic matching testing mechanisms. The security of the scheme is defined by the MLWE and MSIS hard problems, with proofs of keyword ciphertext indistinguishability and trapdoor indistinguishability under the random oracle model. Additionally, the scheme provides strong resistance against both outside and insider keyword guessing attacks through sender–receiver binding mechanisms and trapdoor indistinguishability properties. Experimental results show that, compared to the post-quantum schemes CP-Absel and LB-FSSE, the proposed scheme demonstrates superior overall computational efficiency while maintaining stronger quantum resistance than the traditional scheme SM9-PAEKS.
With the advancement in quantum computing technology, the number theory-based hard problems underlying traditional searchable encryption algorithms are now vulnerable to efficient quantum attacks. To address this challenge, this paper proposes Dilithium-PAEKS (Dilithium-Public Authenticated Encryption with Keyword Search), a searchable encryption scheme based on the post-quantum cryptographic algorithm CRYSTALS-Dilithium. By transforming the verification relationship of digital signatures into a matching relationship between trapdoors and ciphertexts, the scheme not only meets the functional requirements of searchable encryption but also demonstrates quantum resistance. The implementation enhances algorithm efficiency through keyword-based signatures and dynamic matching testing mechanisms. The security of the scheme is defined by the MLWE and MSIS hard problems, with proofs of keyword ciphertext indistinguishability and trapdoor indistinguishability under the random oracle model. Additionally, the scheme provides strong resistance against both outside and insider keyword guessing attacks through sender–receiver binding mechanisms and trapdoor indistinguishability properties. Experimental results show that, compared to the post-quantum schemes CP-Absel and LB-FSSE, the proposed scheme demonstrates superior overall computational efficiency while maintaining stronger quantum resistance than the traditional scheme SM9-PAEKS.
Searchable encryption enables efficient retrieval of encrypted data stored in cloud environments while preserving data confidentiality. Within this context, Public Key Encryption with Keyword Search (PEKS) allows data users to perform keyword-based searches using their public-private key pairs. However, traditional PEKS schemes remain vulnerable to Inside Keyword Guessing Attacks (IKGA), which led to the introduction of the Public-Key Authenticated Encryption with Keyword Search (PAEKS) paradigm to enhance resilience against insider threats. Despite this advancement, most existing PAEKS schemes rely on number-theoretic assumptions, such as the discrete logarithm problem, thereby becoming insecure in the presence of against quantum adversaries. Consequently, recent research has focused on developing quantum-resistant, lattice-based PAEKS schemes. Although schemes based on the Learning with Errors (LWE) problem provide strong post-quantum security, they often incur high computational and communication costs, limiting their practicality in large-scale cloud environments. To overcome these limitations, this work presents an efficient and verifiable PAEKS scheme based on the Middle-Product LWE (MP-LWE) problem, which preserves the underlying security guarantees while significantly improving performance. Formal security analysis demonstrates resistance against Chosen Keyword Attack (CKA) and IKGA in the random oracle (RO) model. Experimental results confirm that the proposed scheme achieves substantially lower computational and communication overheads compared to existing schemes, while maintaining robust post-quantum security.
With the rapid development of cloud computing, an increasing number of companies are adopting cloud storage technology to reduce overhead. However, to ensure the privacy of sensitive data, the uploaded data need to be encrypted before being outsourced to the cloud. The concept of public-key encryption with keyword search (PEKS) was introduced by Boneh et al. to provide flexible usage of the encrypted data. Unfortunately, most of the PEKS schemes are not secure against inside keyword guessing attacks (IKGA), so the keyword information of the trapdoor may be leaked to the adversary. To solve this issue, Huang and Li presented public key authenticated encryption with keyword search (PAEKS) in which the trapdoor generated by the receiver is only valid for authenticated ciphertexts. With their seminal work, many PAEKS schemes have been introduced for the enhanced security of PAEKS. Some of them further consider the upcoming quantum attacks. However, our cryptanalysis indicated that in fact, these schemes could not withstand IKGA. To fight against the attacks from quantum adversaries and support the privacy-preserving search functionality, we first introduce a novel generic PAEKS construction in this work. Then, we further present the first quantum-resistant PAEKS instantiation based on lattices. The security proofs show that our instantiation not only satisfies the basic requirements but also achieves enhanced security models, namely the multi-ciphertext indistinguishability and multi-trapdoor privacy. Furthermore, the comparative results indicate that with only some additional expenditure, the proposed instantiation provides more secure properties, making it suitable for more diverse application environments.
With the improvement of awareness of data privacy, the user's sensitive data are usually encrypted before uploading them to cloud. Searchable encryption is a critical technique on promoting secure and efficient cloud storage. In particular, publickey encryption with keyword search (PEKS) provides an elegant approach to achieve data retrieval in encrypted storage. All existing searchable publickey encryption schemes only provide the security based on classical cryptography hardness assumption. With the development of quantum computers, these schemes will be insecure. Based on the lattice hardness assumptions, we propose a new searchable publickey encryption scheme with a designated tester (dPEKS). Our scheme has advantages: First, our scheme is the first searchable publickey encryption scheme that is considered to be secure even if quantum computers are ever developed. Second, our scheme achieves the trapdoor indistinguishability. The trapdoor indistinguishability implies the security against outside offline keyword guessing attacks (KGAs). Last, our scheme can achieve the trapdoor anonymity for server.
With the improvement of awareness of data privacy, the user's sensitive data are usually encrypted before uploading them to cloud. Searchable encryption is a critical technique on promoting secure and efficient cloud storage. In particular, publickey encryption with keyword search (PEKS) provides an elegant approach to achieve data retrieval in encrypted storage. All existing searchable publickey encryption schemes only provide the security based on classical cryptography hardness assumption. With the development of quantum computers, these schemes will be insecure. Based on the lattice hardness assumptions, we propose a new searchable publickey encryption scheme with a designated tester (dPEKS). Our scheme has advantages: First, our scheme is the first searchable publickey encryption scheme that is considered to be secure even if quantum computers are ever developed. Second, our scheme achieves the trapdoor indistinguishability. The trapdoor indistinguishability implies the security against outside offline keyword guessing attacks (KGAs). Last, our scheme can achieve the trapdoor anonymity for server.
To overcome the issue of traditional blind signature schemes being vulnerable to quantum computing attacks during interactions over the consumer electronic Internet of Things (CIoT), a new blind signature scheme called CDBS has been developed. The post quantum digital signature technique CRYSTALS-Dilithium, which was standardized by NIST, serves as the foundation for the quantum-resistant blind signature scheme, CDBS, presented in this study. This system is appropriate for a variety of internet application scenarios, including e-ticketing, anonymous payments, and privacy protection, because it integrates the idea of blind signatures, which is not included in typical digital signature schemes. This scheme is designed to resist quantum computing attacks and is based on the post-quantum digital signature algorithm CRYSTALS-Dilithium, which NIST has selected. The whole technique utilizes the Fiat-Shamir signature structure, which consists of five stages: key creation, blinding, signing, unblinding, and verification. The security of the proposed scheme is dependent on the resolution of the Module Learning with Errors (MLWE) problem and the Short Integer Solution (SIS) problem. Additionally, the scheme must satisfy the criteria of correctness, blindness, and unforgeability. According to the test results, the CRYSTALS-Dilithium scheme requires an average of 401.89 μ s for a single round of verification and signing. The CDBS technique takes an average of 657.65 ls for one round of signing and verification since the blinding and unblinding modules are added on top of the original algorithm, increasing the algorithm’s complexity. The software testing results indicate that the average time required to complete a single full blind signature and verification operation is 657.65 microseconds. The suggested system offers a framework for expanding the CRYSTALS-Dilithium digital signature algorithm.
Searchable encryption plays a vital role in keeping data privacy of current cloud storage. Considering the security threat of trapdoor exposure, Emura et al. introduced a formal definition of keywords revocable public-key encryption with keywords search (KR-PEKS), which satisfies trapdoor exposure resistance (TER) and trapdoor re-generability. However, there is little work on lattice-based searchable encryption schemes to have the above properties, while it was widely accepted that cryptosystem on lattice has the potential to resist quantum computing attack. In this paper, we give a model of KR-PEKS with novel security, called bounded TER, i.e., a bounded number (previously set) of trapdoors for per keyword are exposed, which cannot affect other keywords. Then, we propose a lattice-based KR-PEKS scheme with bounded TER and trapdoor re-generability and show that this scheme is secure under the hardness assumption of learning with errors (LWE) problem. Finally, we conduct some simulation experiments on our scheme and give a comparison, which indicates that our scheme has less computational cost than the prior arts.