scholarly journals A Constant Round Write-Only ORAM

2020 ◽  
Vol 10 (15) ◽  
pp. 5366
Author(s):  
Bo Zhao ◽  
Zhihong Chen ◽  
Hai Lin ◽  
XiangMin Ji
Keyword(s):  
Binary Tree ◽  
Cloud Storage ◽  
Communication Complexity ◽  
Oblivious Ram

The write-only oblivious RAM (ORAM) is proposed to efficiently protect the privacy of applications such as cloud storage synchronization and encrypted hidden volumes. For N blocks with size B = Ω(log2N), the most efficient write-only ORAM, DetWoORAM, achieves O(B) communication complexity with O(logN) rounds per logical write. We propose a two-level write-only ORAM and achieve O(B) communication complexity with O(1) rounds. Similar to the traditional bucket-based ORAM schemes, we set a rate for the write operation to further reduce the communication complexity. The top-level stores data blocks in a flat array and the write pattern is protected by writing blocks uniformly at random. The second level employs a binary tree to store the position map of data blocks. To avoid recursive storage, a static position map for blocks in the second level is used. Both the analysis and experiments show that, besides the achieved low communication complexity and rounds, the stash sizes in the top level and the second level are bounded to O(B) and ω(B), respectively.

One Cloud: A Secure and Anonymous Multi-Cloud Oblivious Storage Architecture

2014 ◽  
Vol 556-562 ◽  
pp. 5591-5596
Author(s):  
Yi Jie Fan ◽  
Zhen Qiao ◽  
Ming Zhong Xiao
Keyword(s):  
Real World ◽  
Data Security ◽  
Cloud Storage ◽  
Proof Of Concept ◽  
Oblivious Ram ◽  
Oblivious Storage ◽  
Access Patterns ◽  
Key Techniques ◽  
Cloud Storage Services ◽  
Multi Cloud

We present a cross-cloud storage architecture that protects both user’s data and privacy from cloud providers or potential adversaries by leveraging the concept of Oblivious RAM on a logical layer. Our architecture allows users to conceal reading/writing operations and access sequences from clouds in order to prevent the leakage of access patterns, which may be a threat to data security. In addition, an anonymity preserving mechanism applied in our architecture makes it difficult to track users' data or confirm users' identities, which can effectively protect users' privacy. One Cloud, the proof-of-concept prototype of our architecture integrates four major cloud storage services and implements all key techniques we proposed in our architecture. We deploy it in a real-world network environment to analyze and evaluate the performance and the scalability of our architecture.

Oblivious stable sorting protocol and oblivious binary search protocol for secure multi-party computation

2021 ◽  
pp. 1-16
Author(s):  
Ch Koteswara Rao ◽  
Kunwar Singh ◽  
Anoop Kumar
Keyword(s):  
Communication Complexity ◽  
Search Algorithm ◽  
Building Blocks ◽  
Binary Search ◽  
Oblivious Ram ◽  
Detection Systems ◽  
Round Complexity ◽  
Set Intersection ◽  
Private Computation ◽  
Binary Search Algorithm

Multi-party computation (MPC) sorting and searching protocols are frequently used in different databases with varied applications, as in cooperative intrusion detection systems, private computation of set intersection and oblivious RAM. Ivan Damgard et al. have proposed two techniques i.e., bit-decomposition protocol and bit-wise less than protocol for MPC. These two protocols are used as building blocks and have proposed two oblivious MPC protocols. The proposed protocols are based on data-dependent algorithms such as insertion sort and binary search. The proposed multi-party sorting protocol takes the shares of the elements as input and outputs the shares of the elements in sorted order. The proposed protocol exhibits O ( 1 ) constant round complexity and O ( n log n ) communication complexity. The proposed multi-party binary search protocol takes two inputs. One is the shares of the elements in sorted order and the other one is the shares of the element to be searched. If the position of the search element exists, the protocol returns the corresponding shares, otherwise it returns shares of zero. The proposed multi-party binary search protocol exhibits O ( 1 ) round complexity and O ( n log n ) communication complexity. The proposed multi-party sorting protocol works better than the existing quicksort protocol when the input is in almost sorted order. The proposed multi-party searching protocol gives almost the same results, when compared to the general binary search algorithm.

scholarly journals Query-Biased Preview over Outsourced and Encrypted Data

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Ningduo Peng ◽  
Guangchun Luo ◽  
Ke Qin ◽  
Aiguo Chen
Keyword(s):  
Private Information ◽  
Cloud Storage ◽  
Communication Complexity ◽  
Third Party ◽  
Single Server ◽  
Sensitive Data ◽  
Encrypted Data ◽  
Cloud Storage Service ◽  
Dynamic Computation ◽  
Storage Complexity

For both convenience and security, more and more users encrypt their sensitive data before outsourcing it to a third party such as cloud storage service. However, searching for the desired documents becomes problematic since it is costly to download and decrypt each possibly needed document to check if it contains the desired content. An informative query-biased preview feature, as applied in modern search engine, could help the users to learn about the content without downloading the entire document. However, when the data are encrypted, securely extracting a keyword-in-context snippet from the data as a preview becomes a challenge. Based on private information retrieval protocol and the core concept of searchable encryption, we propose a single-server and two-round solution to securely obtain a query-biased snippet over the encrypted data from the server. We achieve this novel result by making a document (plaintext) previewable under any cryptosystem and constructing a secure index to support dynamic computation for a best matched snippet when queried by some keywords. For each document, the scheme hasO(d)storage complexity andO(log(d/s)+s+d/s)communication complexity, wheredis the document size andsis the snippet length.

Integrity Verification for Multiple Data Copies in Cloud Storage Based on Spatiotemporal Chaos

2017 ◽  
Vol 27 (04) ◽  
pp. 1750054 ◽  
Author(s):  
Min Long ◽  
You Li ◽  
Fei Peng
Keyword(s):  
Binary Tree ◽  
Cloud Storage ◽  
Data Privacy ◽  
Spatiotemporal Chaos ◽  
Third Party ◽  
Integrity Verification ◽  
Dynamic Operation ◽  
Multiple Data ◽  
Multiple Copies ◽  
Cloud Storage Services

Aiming to strike for a balance between the security, efficiency and availability of the data verification in cloud storage, a novel integrity verification scheme based on spatiotemporal chaos is proposed for multiple data copies. Spatiotemporal chaos is implemented for node calculation of the binary tree, and the location of the data in the cloud is verified. Meanwhile, dynamic operation can be made to the data. Furthermore, blind information is used to prevent a third-party auditor (TPA) leakage of the users’ data privacy in a public auditing process. Performance analysis and discussion indicate that it is secure and efficient, and it supports dynamic operation and the integrity verification of multiple copies of data. It has a great potential to be implemented in cloud storage services.

Privacy Preserving Public Auditing in Secured Cloud Storage

2012 ◽  
Vol 3 (3) ◽  
pp. 60-61
Author(s):  
V.Sajeev V.Sajeev ◽  
◽  
R.Gowthamani R.Gowthamani
Keyword(s):  
Cloud Storage ◽  
Privacy Preserving ◽  
Public Auditing
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