With the growing need for secure cloud storage and the threat of quantum attacks, we propose a post-quantum secure lattice-based multi-authority attribute-based multi-keyword searchable encryption scheme with dynamic membership. Based on the decisional learning with errors assumption, the proposed scheme resists quantum adversaries while supporting flexible multi-keyword search, decentralized authority to avoid key escrow, and dynamic attribute updates without affecting other users. It enables users to independently generate search tokens, allowing offline authorities and reducing communication overhead. Despite higher encryption costs, experimental results demonstrate that search and decryption remain efficient compared to existing post-quantum lattice-based solutions. The proposed scheme achieves strong data confidentiality and keyword privacy in the post-quantum setting.
With the growing need for secure cloud storage and the threat of quantum attacks, we propose a post-quantum secure lattice-based multi-authority attribute-based multi-keyword searchable encryption scheme with dynamic membership. Based on the decisional learning with errors assumption, the proposed scheme resists quantum adversaries while supporting flexible multi-keyword search, decentralized authority to avoid key escrow, and dynamic attribute updates without affecting other users. It enables users to independently generate search tokens, allowing offline authorities and reducing communication overhead. Despite higher encryption costs, experimental results demonstrate that search and decryption remain efficient compared to existing post-quantum lattice-based solutions. The proposed scheme achieves strong data confidentiality and keyword privacy in the post-quantum setting.
To protect the privacy of cloud data, encryption before uploading provides a solution. However, searching for target data in ciphertext takes effort. Therefore, searchable encryption has become an important research topic. On the other hand, since the advancement of quantum computers will lead to the crisis of cracking traditional encryption algorithms, it is necessary to design encryption schemes that can resist quantum attacks. Therefore, we propose a multi-keyword searchable identity-based proxy re-encryption scheme from lattices. In addition to resisting quantum attacks, the proposed scheme uses several cryptographic techniques to improve encryption efficiency. First, identity-based encryption is used to reduce the computation and transmission costs caused by certificates. Second, the proposed scheme uses proxy re-encryption to achieve the purpose of outsourced computing, allowing the proxy server to reduce the computation and transmission costs of the users. Third, the proposed multi-keyword searchable encryption can provide AND and OR operators to increase the flexibility of searchability. Moreover, the access structure of the proposed scheme is not based on a linear secret sharing scheme (LSSS), avoiding the errors caused by an LSSS-based structure in decryption or search results. Finally, we also give formal security proof of the proposed scheme under the decisional learning with errors assumption.
Attribute-based encryption is useful for one-to-many encrypted message sending. However, most attribute-based encryption schemes authorize and issue attributes to users by a single authority. Such a scenario conflicts with practical requirements and may cause the key-escrow problem. Hence, decentralization of authority is a critical issue in attribute-based encryption. Besides, dynamic membership management is another important issue in attribute-based encryption. With dynamic membership management, a system may update the user’s attributes without affecting other users, making the system more flexible and practical. On the other hand, with the rapid development of quantum computers nowadays, encryption schemes based on traditional mathematical problems are at the risk of quantum attacks. Among the existing quantum-resistant mathematical architectures, lattice-based cryptography is the most widely studied. Thus, we propose a multi-authority attribute-based encryption scheme with dynamic membership from lattices to solve the above problems. Moreover, we also formally prove the security of the proposed scheme under the decisional learning with errors assumption.
Abstract. When data is outsourced to a remote storage server, search-able encryption plays an important role to protect data privacy while allowing users to retrieve data in the massive ciphertext. As far as we know, most of the existing searchable encryption schemes work based on the bilinear map. These schemes may not be secure in the quantum age. Both discrete logarithms and factorization can be solved by quantum computer in a polynomial time. There is very few searchable encryption scheme that can be proved secure in post quantum age. In this paper, in order to construct a post-quantum secure scheme for future cloud stor-age, we suggest a public key encryption with semantic keyword search using the lattice based mechanism. The suggested scheme is proved se-cure against indistinguishable chosen-keyword attacks (IND-CKA) based on learning with errors (LWE) problem. This scheme is believed to be secure in quantum-era due to the quantum intractability of the LWE problem.
Multi-Writer Searchable Encryption, also known as public-key encryption with keyword search(PEKS), serves a wide spectrum of data sharing applications. It allows users to search over encrypted data encrypted via different keys. However, most of the existing PEKS schemes are built on classic security assumptions, which are proven to be untenable to overcome the threats of quantum computers. To address the above problem, in this paper, we propose a lattice-based searchable encryption scheme from the learning with errors (LWE) hardness assumption. Specifically, we observe that the keys of each user in a basic scheme are composed of large-sized matrices and basis of the lattice. To reduce the complexity of key management, our scheme is designed to enable users to directly use their identity for data encryption. We present several optimization techniques for implementation to make our design nearly practical. For completeness, we conduct rigorous security, complexity, and parameter analysis on our scheme, and perform comprehensive evaluations at a commodity machine. With a scenario of 100 users, the cost of key generation for each user is 125s, and the cost of searching a document with 1000 keywords is 13.4ms.
To address the risks of data leakage and unauthorized access in Intelligent Transportation Systems (ITS), particularly in the post-quantum era where traditional cryptographic algorithms are vulnerable, this paper proposes a novel Post-Quantum Attribute-Based Searchable Encryption (PQ-ABSE) scheme. The scheme is designed to resist quantum attacks while providing privacy-preserving search, key aggregation, and lightweight computation. The proposed PQ-ABSE scheme ensures end-to-end privacy protection during key generation, access control, and partial decryption phases. By embedding search keywords into the access policy, it achieves partial policy hiding and ensures keyword confidentiality under quantum-resilient assumptions. Moreover, by leveraging key aggregation techniques, the scheme consolidates all file identifiers that meet both the search and access conditions into a single aggregate key, significantly reducing user-side key storage overhead while ensuring file and data security. Security analysis confirms that the scheme achieves hidden access structure security, keyword ciphertext indistinguishability, and trapdoor indistinguishability in a post-quantum setting. Theoretical analysis and simulation results further demonstrate the scheme’s practicality and efficiency in terms of both computational and communication overhead, making it a promising solution for post-quantum secure ITS data management.
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.