Secure K-nearest Neighbor Research Articles

Verifiable privacy-preserving semantic retrieval scheme in the edge computing

Edge computing, with its characteristics of low latency and low transmission costs, addresses the storage and computation challenges arising from the surge in network edge traffic. It enables users to leverage nearby edge servers for data outsourcing and retrieval. However, data outsourcing poses risks to data privacy. Although searchable encryption is proposed to secure search of outsourced data, existing schemes generally cannot meet the requirements of semantic search, and they also exhibit security risks and incur high search costs. In addition, edge servers may engage in malicious activities such as data tampering or forgery. Therefore, we propose a verifiable privacy-preserving semantic retrieval scheme named VPSR suitable for edge computing environments. We utilize the Doc2Vec method to extract text feature vectors and then convert them into matrix form to reduce storage space requirements for indexes, queries, and keys. We encrypt matrices using an improved secure k-nearest neighbor (kNN) algorithm based on learning with errors (LWE) and calculate text similarity by solving the Hadamard product between matrices. Additionally, we design an aggregable signature scheme and offload part of the result verification tasks to edge servers. Security and performance analysis results demonstrate that the VPSR scheme is suitable for edge computing environments with high encryption and search efficiency and low storage cost while ensuring security.

Efficient and Expressive Search Scheme over Encrypted Electronic Medical Records

In recent years, there has been rapid development in computer technology, leading to an increasing number of medical systems utilizing electronic medical records (EMRs) to store their clinical data. Because EMRs are very private, healthcare institutions usually encrypt these data before transferring them to cloud servers. A technique known as searchable encryption (SE) can be used by healthcare institutions to encrypt EMR data. This technique enables searching within the encrypted data without the need for decryption. However, most existing SE schemes only support keyword or range searches, which are highly inadequate for EMR data as they contain both textual and digital content. To address this issue, we have developed a novel searchable symmetric encryption scheme called SSE-RK, which is specifically designed to support both range and keyword searches, and it is easily applicable to EMR data. We accomplish this by creating a conversion technique that turns keywords and ranges into vectors. These vectors are then used to construct index tree building and search algorithms that enable simultaneous range and keyword searches. We encrypt the index tree using a secure K-Nearest Neighbor technique, which results in an effective SSE-RK approach with a search complexity that is quicker than a linear approach. Theoretical and experimental study further demonstrates that our proposed scheme surpasses previous similar schemes in terms of efficiency. Formal security analysis demonstrates that SSE-RK protects privacy for both data and queries during the search process. Consequently, it holds significant potential for a wide range of applications in EMR data. Overall, our SSE-RK scheme, which offers improved functionality and efficiency while protecting the privacy of EMR data, generally solves the shortcomings of the current SE schemes.

Indexing dynamic encrypted database in cloud for efficient secure k-nearest neighbor query

Indexing dynamic encrypted database in cloud for efficient secure k-nearest neighbor query

Achieving Secure and Efficient Dynamic Searchable Symmetric Encryption over Medical Cloud Data

In medical cloud computing, a patient can send her medical data to a cloud server from afar. Because medical data is highly sensitive, only authorized doctors are allowed to access it in this case. A frequent solution is to encrypt data before outsourcing it, with the patient simply sending the corresponding encryption key to the authorized doctors. However, due to the difficulties of digging through the encrypted data, the usability of outsourced medical data is severely limited. Over medical cloud data, we propose Secure and Efficient Dynamic Searchable Symmetric Encryption (SEDSSE) schemes. To begin, we propose a dynamic searchable symmetric encryption scheme that uses the secure k-Nearest Neighbor (kNN) and Attribute-Based Encryption (ABE) techniques to achieve two important security features: forward privacy and backward privacy, both of which are difficult to achieve in the field of dynamic searchable symmetric encryption. Then, to address the key sharing problem that plagues the kNN-based searchable encryption strategy, we suggest an improved technique. In terms of storage, search, and update complexity, our solutions outperform prior proposals. Extensive tests show that our approaches are efficient in terms of storage overhead, index building, trapdoor generation, and query.

Secure and Verifiable Multikey Image Search in Cloud-Assisted Edge Computing

With the development of outsourcing services, users with limited resources tend to store encrypted images on remote servers and search them anytime and anywhere. However, existing encrypted image search schemes are proposed for cloud computing scenarios, and have some defects, such as excessive bandwidth resource consumption or network delay, which are not suitable for Internet of Things (IoT) devices in edge computing environment. Therefore, we propose a secure and verifiable multikey image search (SVMIS) scheme in cloud-assisted edge computing. First, the pretrained convolutional neural network model is employed to extract image feature vectors to improve search accuracy. Then, a key distribution protocol is designed to convert the encrypted indexes of different owners, and a transformation key list is constructed to support the multikey setting in edge computing. Next, the learning with errors based secure k-nearest neighbor algorithm is used to encrypt feature vectors to improve security. Finally, the Merkle hash tree is utilized to check the correctness of search results returned by edge servers. Theoretical analysis and extensive experiments using a real-world dataset evaluate the security and effectiveness of SVMIS.

Secure K-Nearest neighbor queries in two-tiered mobile wireless sensor networks

Tiered Mobile Wireless Sensor Network(TMWSN) is a new paradigm introduced by mobile edge computing. Now it has received wide attention because of its high scalability, robustness, deployment flexibility, and it has a wide range of application scenarios. In TMWSNs, the storage nodes are the key nodes of the network and are more easily captured and utilized by attackers. Once the storage nodes are captured by the attackers, the data stored on them will be exposed. Moreover, the query process and results will not be trusted any more. This paper mainly studies the secure KNN query technology in TMWSNs, and we propose a secure KNN query algorithm named the Basic Algorithm For Secure KNN Query(BAFSKQ) first, which can protect privacy and verify the integrity of query results. However, this algorithm has a large communication overhead in most cases. In order to solve this problem, we propose an improved algorithm named the Secure KNN Query Algorithm Based on MR-Tree(SEKQAM). The MR-Trees are used to find the K-nearest locations and help to generate a verification set to process the verification of query results. It can be proved that our algorithms can effectively guarantee the privacy of the data stored on the storage nodes and the integrity of the query results. Our experimental results also show that after introducing the MR-Trees in KNN queries on TMWSNs, the communication overhead has an effective reduction compared to BAFSKQ.

Privacy-preserving searchable encryption in the intelligent edge computing

In intelligent edge computing, the private data of users are partly or entirely outsourced to the intelligent edge nodes for processing. To enforce security and privacy on edge network, data owners encrypt their private data and outsource it. It is particularly important to carry out efficient search and update on encrypted data. In this paper, we propose a searchable scheme to solve these problems on the intelligent edge network. Specially, we first propose S-HashMap index structure to make data update efficiently and safely while promising multi-keyword fuzzy ciphertext retrieval. Secondly, to measure the similarity between the query vector and the index nodes, we utilize the secure k-nearest neighbor to calculate the Euclidean distance. In addition to eliminating the necessity of pre-defined dictionaries, we achieve efficient multi-keyword fuzzy search and index updating without increasing search complexity. At the same time, this paper makes a thorough theoretical analysis and simulation of the proposed scheme. Compared with other schemes, we demonstrate that our scheme has better security and efficiency.

Efficient and secure k-nearest neighbor query on outsourced data

Efficient and secure k-nearest neighbor query on outsourced data

Toward Efficient Encrypted Image Retrieval in Cloud Environment

Outsourcing image search services to public clouds is an ever-increasing trend. However, directly outsourcing image datasets to untrusted clouds introduces privacy concerns. Several secure image retrieval schemes have been proposed recently. However, most of them require participation from image owners when building secure indexes, which wastes many computational resources of the image owners. Several schemes are proposed to solve this problem, but they suffer from low search accuracy on large datasets. In this paper, we propose the first secure image retrieval scheme that simultaneously solves these two problems. To obtain higher search accuracy, we extract image features via fine-tuned convolutional neural networks. Then, the image features are encrypted by using the secure k-Nearest Neighbor algorithm. To improve search speed and reduce the cost of image owners, we let cloud servers locally build a secure hierarchical index graph by using the encrypted image features. Besides, the secure index can be built and updated in parallel. We provide security analysis for the proposed scheme. Performance evaluations on the CIFAR-10 dataset show that the proposed scheme is practical. Moreover, compared with a recent scheme, our scheme can save more index construction time and cost of image owners when building secure indexes.

Achieving Secure and Efficient Dynamic Searchable Symmetric Encryption over Medical Cloud Data

In medical cloud computing, a patient can remotely outsource her medical data to the cloud server. In this case, only authorized doctors are allowed to access the data since the medical data is highly sensitive. Before outsourcing, the data is commonly encrypted, where the corresponding secret key is sent to authorized doctors. However, performing searches on encrypted medical data is difficult without decryption. In this paper, we propose two Secure and Efficient Dynamic Searchable Symmetric Encryption (SEDSSE) schemes over medical cloud data. First, we utilize the secure k-Nearest Neighbor (kNN) and Attribute-Based Encryption (ABE) techniques to construct a dynamic searchable symmetric encryption scheme, which can achieve forward privacy and backward privacy simultaneously. These tow security properties are vital and very challenging in the area of dynamic searchable symmetric encryption. Then, we propose an enhanced scheme to solve the key sharing problem which widely exists in the kNN based searchable encryption scheme. Compared with existing proposals, our schemes are better in terms of storage, search and updating complexity. Extensive experiments demonstrate the efficiency of our schemes on storage overhead, index building, trapdoor generating and query.

EPCBIR: An efficient and privacy-preserving content-based image retrieval scheme in cloud computing

The content-based image retrieval (CBIR) has been widely studied along with the increasing importance of images in our daily life. Compared with the text documents, images consume much more storage and thus are very suitable to be stored on the cloud servers. The outsourcing of CBIR to the cloud servers can be a very typical service in cloud computing. For the privacy-preserving purposes, sensitive images, such as medical and personal images, need to be encrypted before being outsourced, which will cause the CBIR technologies in plaintext domain unusable. In this paper, we propose a scheme that supports CBIR over the encrypted images without revealing the sensitive information to the cloud server. Firstly, the feature vectors are extracted to represent the corresponding images. Then, the pre-filter tables are constructed with the locality-sensitive hashing to increase the search efficiency. Next, the feature vectors are protected by the secure k-nearest neighbor (kNN) algorithm. The security analysis and experiments show the security and efficiency of the proposed scheme.