Open AccessPosted Content
PORs: Proofs of Retrievability for Large Files
Ari Juels,Burton S. Kaliski +1 more
TLDR
This paper defines and explores proofs of retrievability (PORs), a POR scheme that enables an archive or back-up service to produce a concise proof that a user can retrieve a target file F, that is, that the archive retains and reliably transmits file data sufficient for the user to recover F in its entirety.Abstract:
In this paper, we define and explore proofs of retrievability (PORs). A POR scheme enables an archive or back-up service (prover) to produce a concise proof that a user (verifier) can retrieve a target file F, that is, that the archive retains and reliably transmits file data sufficient for the user to recover F in its entirety.A POR may be viewed as a kind of cryptographic proof of knowledge (POK), but one specially designed to handle a large file (or bitstring) F. We explore POR protocols here in which the communication costs, number of memory accesses for the prover, and storage requirements of the user (verifier) are small parameters essentially independent of the length of F. In addition to proposing new, practical POR constructions, we explore implementation considerations and optimizations that bear on previously explored, related schemes.In a POR, unlike a POK, neither the prover nor the verifier need actually have knowledge of F. PORs give rise to a new and unusual security definition whose formulation is another contribution of our work.We view PORs as an important tool for semi-trusted online archives. Existing cryptographic techniques help users ensure the privacy and integrity of files they retrieve. It is also natural, however, for users to want to verify that archives do not delete or modify files prior to retrieval. The goal of a POR is to accomplish these checks without users having to download the files themselves. A POR can also provide quality-of-service guarantees, i.e., show that a file is retrievable within a certain time bound.read more
Citations
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Book ChapterDOI
Knox: privacy-preserving auditing for shared data with large groups in the cloud
Boyang Wang,Baochun Li,Hui Li +2 more
TL;DR: Knox, a privacy-preserving auditing mechanism for data stored in the cloud and shared among a large number of users in a group, utilizes group signatures to construct homomorphic authenticators, so that a third party auditor (TPA) is able to verify the integrity of shared data for users without retrieving the entire data.
Proceedings ArticleDOI
Provenance for the cloud
TL;DR: The case is made that provenance is crucial for data stored on the cloud and identify the properties of provenance that enable its utility and the case for incorporating provenance as a core cloud feature, discussing the issues in doing so.
Book ChapterDOI
Careful with composition: limitations of the indifferentiability framework
TL;DR: A hash-based storage auditing scheme which is provably secure in the random-oracle model (ROM), but easily broken when one instead uses typical indifferentiable hash constructions, contradicting the widely accepted belief that the indifferentiability composition theorem applies to any cryptosystem.
Journal ArticleDOI
MuR-DPA: Top-Down Levelled Multi-Replica Merkle Hash Tree Based Secure Public Auditing for Dynamic Big Data Storage on Cloud
TL;DR: MuR-DPA as mentioned in this paper is a public data auditing scheme based on the Merkle hash tree (MHT), which can not only incur much less communication overhead for both update verification and integrity verification of cloud datasets with multiple replicas, but also provide enhanced security against dishonest cloud service providers.
Journal ArticleDOI
Oruta: Privacy-Preserving Public Auditingfor Shared Data in the Cloud
Boyang Wang,Baochun Li,Hui Li +2 more
TL;DR: This paper proposes a novel privacy-preserving mechanism that supports public auditing on shared data stored in the cloud that exploits ring signatures to compute verification metadata needed to audit the correctness of shared data.
References
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S. Subashini,V. Kavitha +1 more
TL;DR: A survey of the different security risks that pose a threat to the cloud is presented and a new model targeting at improving features of an existing model must not risk or threaten other important features of the current model.
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TL;DR: Information Dispersal Algorithm (IDA) has numerous applications to secure and reliable storage of information in computer networks and even on single disks, to fault-tolerant and efficient transmission ofInformation in networks, and to communications between processors in parallel computers.
Posted Content
Provable Data Possession at Untrusted Stores.
Giuseppe Ateniese,Randal Burns,Reza Curtmola,Joseph Herring,Lea Kissner,Zachary N. J. Peterson,Dawn Song +6 more
TL;DR: Ateniese et al. as discussed by the authors introduced the provable data possession (PDP) model, which allows a client that has stored data at an untrusted server to verify that the server possesses the original data without retrieving it.
Book ChapterDOI
The knowledge complexity of interactive proof-systems
TL;DR: Permission to copy without fee all or part of this material is granted provided that the copies arc not made or distributed for direct commercial advantage.
Proceedings Article
Raptor codes
TL;DR: For a given integer k, and any real /spl epsiv/>0, Raptor codes in this class produce a potentially infinite stream of symbols such that any subset of symbols of size k(1 + /spl Epsiv/) is sufficient to recover the original k symbols, with high probability as mentioned in this paper.