With the popularity of cloud computing, a large number of personal and corporate data are outsourced to the cloud. This centralized storage and processing mode not only improves the efficiency of data processing, but also brings challenges to data security and privacy. In view of the development of quantum computing, the traditional public key encryption may no longer be secure in the future. Therefore, it is particularly important to study the public key authenticated keyword searchable encryption (PEAKS) scheme which can resist quantum. This scheme can provide double guarantee for the data in cloud storage: one is to ensure the confidentiality of the data, so that the original content cannot be decrypted even within the cloud service provider; the other is to allow users to perform keyword searches on encrypted data without decrypting the data. This provides a balance of security and efficiency for data search and analysis in cloud computing environment. Recently, Genise et al. designed a Gadget-based iNTRU trapdoor, which has the advantages of small size and high efficiency. Therefore, we design an efficient and secure public key authentication keyword searchable encryption scheme based on iNTRU lattice. The overall running time of this scheme is only more than 300ms.
With the popularity of cloud computing, a large number of personal and corporate data are outsourced to the cloud. This centralized storage and processing mode not only improves the efficiency of data processing, but also brings challenges to data security and privacy. In view of the development of quantum computing, the traditional public key encryption may no longer be secure in the future. Therefore, it is particularly important to study the public key authenticated keyword searchable encryption (PEAKS) scheme which can resist quantum. This scheme can provide double guarantee for the data in cloud storage: one is to ensure the confidentiality of the data, so that the original content cannot be decrypted even within the cloud service provider; the other is to allow users to perform keyword searches on encrypted data without decrypting the data. This provides a balance of security and efficiency for data search and analysis in cloud computing environment. Recently, Genise et al. designed a Gadget-based iNTRU trapdoor, which has the advantages of small size and high efficiency. Therefore, we design an efficient and secure public key authentication keyword searchable encryption scheme based on iNTRU lattice. The overall running time of this scheme is only more than 300ms.
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.
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 widespread development of database systems, data security has become crucial when it comes to sharing among users and servers. A straightforward approach involves using searchable encryption to ensure the confidentiality of shared data. However, in certain scenarios, varying user tiers are granted disparate data searching privileges, and administrators need to restrict the searchability of ciphertexts to select users exclusively. To address this issue, public key encryption with authorized keyword search (PEAKS) was proposed, wherein solely authorized users possess the ability to conduct targeted keyword searches. Nonetheless, it is vulnerable to resist quantum computing attacks. As a result, research focusing on authorizing users to search for keywords while achieving quantum security is far-reaching. In this paper, we propose a lattice-based variant of PEAKS (L-PEAKS) that enables keyword dataset authorization for outsourced data management. Unlike existing schemes, our design incorporates identity-based encryption (IBE) to overcome the bottleneck of public key management. Besides, we utilize several lattice sampling algorithms to defend against attacks from quantum adversaries. Specifically, each authorized user must obtain a search privilege from an authority. The authority distributes an authorized token to the user within a specific time period, and the user generates a trapdoor for any authorized keywords. Our scheme is proven to be secure against IND-sID-CKA and T-EUF security in a quantum setting. We also conduct comprehensive evaluations on a commodity machine to assess completeness and provide theoretical complexity comparisons with existing state-of-the-art schemes.
To ensure the privacy and security of the stored data, the data can be encrypted first and then stored on the cloud. However, it faces the problem that users cannot search keywords in a large amount of data, which limits the flexibility of file sharing in the cloud environment. Searchable encryption can effectively support users to retrieve encrypted data in the cloud. Public key searchable encryption (PEKS) is used to retrieve the target encrypted data by searching specific keywords. However, the development of quantum computers has led to attacks on conventional encryption algorithms, and it is necessary to design searchable encryption schemes that can resist quantum attacks. Therefore, we propose a lattice puncturable PEKS scheme. Besides resisting quantum attacks, the proposed scheme attains efficient and flexible user revocation. Firstly, identity-based encryption is employed to minimize the complexity of key management. Secondly, the puncturable encryption technology is integrated into the proposed encryption to revoke the decryption capability for selected messages, enabling authorized recipients to repeatedly update their decryption keys to retrieve the currently encrypted messages. Finally, we prove the security of our scheme under the indistinguishability against chosen keyword attack (IND-PUN-sID-CKA), and conduct a comparison with other schemes to emphasize its advantages. Although the scheme does not have an edge in size, it holds an advantage in key update after adding the puncture function and also realizes higher security.