863 research outputs found
A Survey on Homomorphic Encryption Schemes: Theory and Implementation
Legacy encryption systems depend on sharing a key (public or private) among
the peers involved in exchanging an encrypted message. However, this approach
poses privacy concerns. Especially with popular cloud services, the control
over the privacy of the sensitive data is lost. Even when the keys are not
shared, the encrypted material is shared with a third party that does not
necessarily need to access the content. Moreover, untrusted servers, providers,
and cloud operators can keep identifying elements of users long after users end
the relationship with the services. Indeed, Homomorphic Encryption (HE), a
special kind of encryption scheme, can address these concerns as it allows any
third party to operate on the encrypted data without decrypting it in advance.
Although this extremely useful feature of the HE scheme has been known for over
30 years, the first plausible and achievable Fully Homomorphic Encryption (FHE)
scheme, which allows any computable function to perform on the encrypted data,
was introduced by Craig Gentry in 2009. Even though this was a major
achievement, different implementations so far demonstrated that FHE still needs
to be improved significantly to be practical on every platform. First, we
present the basics of HE and the details of the well-known Partially
Homomorphic Encryption (PHE) and Somewhat Homomorphic Encryption (SWHE), which
are important pillars of achieving FHE. Then, the main FHE families, which have
become the base for the other follow-up FHE schemes are presented. Furthermore,
the implementations and recent improvements in Gentry-type FHE schemes are also
surveyed. Finally, further research directions are discussed. This survey is
intended to give a clear knowledge and foundation to researchers and
practitioners interested in knowing, applying, as well as extending the state
of the art HE, PHE, SWHE, and FHE systems.Comment: - Updated. (October 6, 2017) - This paper is an early draft of the
survey that is being submitted to ACM CSUR and has been uploaded to arXiv for
feedback from stakeholder
Mental Card Gaming Protocols Supportive Of Gameplay Versatility, Robustness And Efficiency
Pennainan kad mental merupakan protokol kriptografi yang membolehkan pennainan yang
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disahkan adil di kalangan parti-parti jauh yang penyangsi dan berpotensi menipu. Pennainan
kad ini setidak-tidaknya patut menyokong-tanpa memperkenal~an parti ketiga yang dipercayai
(TTP)--rahsia kad, pengesanan penipuan dan keselamatan bersyarat ke atas pakatan pemain.
Tambahan kepada keperJuan asas ini, kami meninjau isu-isu pennainan kad mental yang
berkaitan dengan fungsian permainan, keteguhan operasional dan kecekapan implementasi.
Pengkajian kami diberangsang oleh potensi pennainan berasaskan komputer dan rangkaian yang
melewati batas kemampuan kad fizikal, terutamanya pembongkaran maklumat terperinci kad
(seperti warna, darjat, simbol atau kebangsawanan) sambil merahsiakan nilai keseluruhan kad
tersebut.
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Mental card games are cryptographic protocols which permit verifiably fair gameplay among a
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priori distrustful and potentially untrustworthy remote parties and should minimally providewithout
the introduction of a trusted third party (TTP)---for card confidentiality, fraud detection
and conditional security against collusion. In addition to these basic requirements, we explore
into gameplay functionality, operational robustness and implementation efficiency issues of
mental card gaming. Our research is incited by the potential of computer-based and networkmediated
gameplay beyond the capability of physical cards, particularly fine-grained
information disclosure (such as colour, rank, symbol or courtliness) with preservation of card
secrecy. On the other hand, being network connected renders the protocol susceptible to
(accidental or intentional) disconnection attack, as well as other malicious behaviours
Public-key cryptography and invariant theory
Public-key cryptosystems are suggested based on invariants of groups. We give
also an overview of the known cryptosystems which involve groups.Comment: 10 pages, LaTe
Survey on Efficient Information Retrieval for Ranked Query in Cost-Efficient Clouds
Cloud computing technology redefines the advances in information technology. The most challenging research works in cloud computing is privacy and protection of data. Cloud computing provides an innovative business model for organizations with minimal investment. Cloud computing has emerged as a major driver in reducing the information technology costs incurred by organizations. Security is one of the major issues in cloud computing. So it is necessary to protect the user privacy while querying the data in the cloud environment, different techniques are developed by researchers to provide privacy, but the computational and bandwidth costs increased which are unacceptable to the users. This paper presents description and comparison of Ostrovsky, COPS and EIRQ protocols which are currently available for retrieving information from clouds. EIRQ protocol is the latest among these protocols and it addresses the issues of privacy, aggregation, CPU consumption and network bandwidth usage
Formal Analysis of CRT-RSA Vigilant's Countermeasure Against the BellCoRe Attack: A Pledge for Formal Methods in the Field of Implementation Security
In our paper at PROOFS 2013, we formally studied a few known countermeasures
to protect CRT-RSA against the BellCoRe fault injection attack. However, we
left Vigilant's countermeasure and its alleged repaired version by Coron et al.
as future work, because the arithmetical framework of our tool was not
sufficiently powerful. In this paper we bridge this gap and then use the same
methodology to formally study both versions of the countermeasure. We obtain
surprising results, which we believe demonstrate the importance of formal
analysis in the field of implementation security. Indeed, the original version
of Vigilant's countermeasure is actually broken, but not as much as Coron et
al. thought it was. As a consequence, the repaired version they proposed can be
simplified. It can actually be simplified even further as two of the nine
modular verifications happen to be unnecessary. Fortunately, we could formally
prove the simplified repaired version to be resistant to the BellCoRe attack,
which was considered a "challenging issue" by the authors of the countermeasure
themselves.Comment: arXiv admin note: substantial text overlap with arXiv:1401.817
A New PVSS Scheme with a Simple Encryption Function
A Publicly Verifiable Secret Sharing (PVSS) scheme allows anyone to verify
the validity of the shares computed and distributed by a dealer. The idea of
PVSS was introduced by Stadler in [18] where he presented a PVSS scheme based
on Discrete Logarithm. Later, several PVSS schemes were proposed. In [2],
Behnad and Eghlidos present an interesting PVSS scheme with explicit membership
and disputation processes. In this paper, we present a new PVSS having the
advantage of being simpler while offering the same features.Comment: In Proceedings SCSS 2012, arXiv:1307.8029. This PVSS scheme was
proposed to be used to provide a distributed Timestamping schem
Privacy-Aware Processing of Biometric Templates by Means of Secure Two-Party Computation
The use of biometric data for person identification and access control is gaining more and more popularity. Handling biometric data, however, requires particular care, since biometric data is indissolubly tied to the identity of the owner hence raising important security and privacy issues. This chapter focuses on the latter, presenting an innovative approach that, by relying on tools borrowed from Secure Two Party Computation (STPC) theory, permits to process the biometric data in encrypted form, thus eliminating any risk that private biometric information is leaked during an identification process. The basic concepts behind STPC are reviewed together with the basic cryptographic primitives needed to achieve privacy-aware processing of biometric data in a STPC context. The two main approaches proposed so far, namely homomorphic encryption and garbled circuits, are discussed and the way such techniques can be used to develop a full biometric matching protocol described. Some general guidelines to be used in the design of a privacy-aware biometric system are given, so as to allow the reader to choose the most appropriate tools depending on the application at hand
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