An effective, secure and efficient tagging method for integrity protection of outsourced data in a public cloud storage

Data Integrity Auditing (DIA) is a security service for checking the integrity of data stored in a PCS (Public Cloud Storage), a third-party based storage service. A DIA service is provided by using integrity tags (hereafter referred to tags). This paper proposes a novel tagging method, called Tagging of Outsourced Data (TOD), for generating and verifying tags of files. TOD has a number of unique properties: (i) it supports both public and private verifiability, and achieves this property with a low level of overhead at the user end, making it particularly attractive to mobile users with resource-constrained devices, (ii) it protects data confidentiality, supports dynamic tags and is resilient against tag forgery and tag tampering (i.e. by authorised insiders) at the same time in more secure and efficient, making the method more suited to the PCS environment, (iii) it supports tags deduplication, making it more efficient, particularly for the user who has many files with data redundancy. Comprehensive security analysis and performance evaluation have been conducted to demonstrate the efficacy and efficiency of the approach taken in the design

Co-Check: Collaborative Outsourced Data Auditing in Multicloud Environment

With the increasing demand for ubiquitous connectivity, wireless technology has significantly improved our daily lives. Meanwhile, together with cloud-computing technology (e.g., cloud storage services and big data processing), new wireless networking technology becomes the foundation infrastructure of emerging communication networks. Particularly, cloud storage has been widely used in services, such as data outsourcing and resource sharing, among the heterogeneous wireless environments because of its convenience, low cost, and flexibility. However, users/clients lose the physical control of their data after outsourcing. Consequently, ensuring the integrity of the outsourced data becomes an important security requirement of cloud storage applications. In this paper, we present Co-Check, a collaborative multicloud data integrity audition scheme, which is based on BLS (Boneh-Lynn-Shacham) signature and homomorphic tags. According to the proposed scheme, clients can audit their outsourced data in a one-round challenge-response interaction with low performance overhead. Our scheme also supports dynamic data maintenance. The theoretical analysis and experiment results illustrate that our scheme is provably secure and efficient

Privacy Preserving Public Auditing and Data Integrity for Secure Cloud Storage Using Third Party Auditor

Using cloud services, anyone can remotely store their data and can have the on-demand high quality applications and services from a shared pool of computing resources, without the burden of local data storage and maintenance. Cloud is a commonplace for storing data as well as sharing of that data. However, preserving the privacy and maintaining integrity of data during public auditing remains to be an open challenge. In this paper, we introducing a third party auditor (TPA), which will keep track of all the files along with their integrity. The task of TPA is to verify the data, so that the user will be worry-free. Verification of data is done on the aggregate authenticators sent by the user and Cloud Service Provider (CSP). For this, we propose a secure cloud storage system which supports privacy-preserving public auditing and blockless data verification over the cloud

Smarter Data Availability Checks in the Cloud: Proof of Storage via Blockchain

Cloud computing offers clients flexible and cost-effective resources. Nevertheless, past incidents indicate that the cloud may misbehave by exposing or tampering with clients' data. Therefore, it is vital for clients to protect the confidentiality and integrity of their outsourced data. To address these issues, researchers proposed cryptographic protocols called “proof of storage” that let a client efficiently verify the integrity or availability of its data stored in a remote cloud server. However, in these schemes, the client either has to be online to perform the verification itself or has to delegate the verification to a fully trusted auditor. In this chapter, a new scheme is proposed that lets the client distribute its data replicas among multiple cloud servers to achieve high availability without the need for the client to be online for the verification and without a trusted auditor's involvement. The new scheme is mainly based on blockchain smart contracts. It illustrates how a combination of cloud computing and blockchain technology can resolve real-world problems

ACTIVE-HASH-TABLE BASED PUBLIC AUDITING FOR SECURE CLOUD STORAGE

Public auditing scheme for secure cloud storage based on dynamic hash table, which is a new two-dimensional data structure located at a third-party auditor (TPA) to record the data property information for dynamic auditing. Differing form the existing works, the proposed scheme migrates the authorized information from the cloud services provider to the TPA and thereby significantly reduces the computational cost and communication overhead. Our scheme can also achieve higher updating efficiency than the state of the art schemes. In addition, we extend our scheme to support privacy preservation by combining the homomorphic authenticator based on the public key with the random masking generated by the TPA and achieve batch auditing by employing the aggregate BLS signature technique. We formally prove the security of the proposed scheme and evaluate the auditing performance by detailed experiments and comparisons with the existing ones. The results demonstrate that the proposed scheme can effectively achieve secure auditing for cloud storage and outperform the previous schemes’ in computation complexity, storage costs, and communication overhead

Efficient integrity verification of replicated data in cloud

The cloud computing is an emerging model in which computing infrastructure resources are provided as a service over the Internet. Data owners can outsource their data by remotely storing them in the cloud and enjoy on-demand high quality services from a shared pool of configurable computing resources. By using these data storage services, the data owners can relieve the burden of local data storage and maintenance. However, since data owners and the cloud servers are not in the same trusted domain, the outsourced data may be at risk as the cloud server may no longer be fully trusted. Therefore, data integrity is of critical importance in such a scenario. Cloud should let the owners or a trusted third party to check for the integrity of their data storage without demanding a local copy of the data. Owners often replicate their data on the cloud servers across multiple data centers to provide a higher level of scalability, availability, and durability. When the data owners ask the Cloud Service Provider (CSP) to replicate data, they are charged a higher storage fee by the CSP. Therefore, the data owners need to be strongly convinced that the CSP is storing data copies agreed on in the service level contract, and data-updates have been correctly executed on all the remotely stored copies. In this thesis, a Dynamic Multi-Replica Provable Data Possession scheme (DMR-PDP) is proposed that prevents the CSP from cheating; for example, by maintaining fewer copies than paid for and/or tampering data. In addition, we also extended the scheme to support a basic file versioning system where only the difference between the original file and the updated file is propagated rather than the propagation of operations for privacy reasons. DMR-PDP also supports efficient dynamic operations like block modification, insertion and deletion on replicas over the cloud servers --Abstract, page iii

FSPVDsse: A Forward Secure Publicly Verifiable Dynamic SSE scheme

A symmetric searchable encryption (SSE) scheme allows a client (data owner) to search on encrypted data outsourced to an untrusted cloud server. The search may either be a single keyword search or a complex query search like conjunctive or Boolean keyword search. Information leakage is quite high for dynamic SSE, where data might be updated. It has been proven that to avoid this information leakage an SSE scheme with dynamic data must be forward private. A dynamic SSE scheme is said to be forward private, if adding a keyword-document pair does not reveal any information about the previous search result with that keyword. In SSE setting, the data owner has very low computation and storage power. In this setting, though some schemes achieve forward privacy with honest-but-curious cloud, it becomes difficult to achieve forward privacy when the server is malicious, meaning that it can alter the data. Verifiable dynamic SSE requires the server to give a proof of the result of the search query. The data owner can verify this proof efficiently. In this paper, we have proposed a generic publicly verifiable dynamic SSE (DSSE) scheme that makes any forward private DSSE scheme verifiable without losing forward privacy. The proposed scheme does not require any extra storage at owner-side and requires minimal computational cost as well for the owner. Moreover, we have compared our scheme with the existing results and show that our scheme is practical.Comment: 17 pages, Published in ProvSec 201