455 research outputs found
Rate-limited secure function evaluation
We introduce the notion of rate-limited secure function evaluation (RL-SFE). Loosely speaking, in an RL-SFE protocol participants can monitor and limit the number of distinct inputs (i.e., rate) used by their counterparts in multiple executions of an SFE, in a private and verifiable manner. The need for RL-SFE naturally arises in a variety of scenarios: e.g., it enables service providers to “meter” their customers’ usage without compromising their privacy, or can be used to prevent oracle attacks against SFE constructions. We consider three variants of RL-SFE providing different levels of security. As a stepping
stone, we also formalize the notion of commit-first SFE (CF-SFE) wherein parties are committed to their inputs before each SFE execution. We provide compilers for transforming any CF-SFE protocol into each of the three RL-SFE variants. Our compilers are accompanied with simulation-based proofs of security in the standard model and show a clear tradeoff between the level of security offered and the overhead required. Moreover, motivated by the fact that in many client-server applications clients do not keep state, we also describe a general approach for transforming the resulting RL-SFE protocols into stateless ones. As a case study, we take a closer look at the oblivious polynomial evaluation (OPE) protocol of Hazay and Lindell, show that it is commit-first, and instantiate efficient ratelimited variants of it
Modeling of bend discontinuity in plasmonic and spoof plasmonic waveguides
The paper proposes a method to characterize the bend discontinuity for
plasmonic and spoof plasmonic waveguides in terms of scattering parameters. By
means of this method, the waveguide is modelled by a two-port network and its
scattering parameters are extracted. The parameters for the L-shaped sharp
curved bends at different frequencies and under different bending angles are
determined
COVID-19 Diagnosis: ULGFBP-ResNet51 approach on the CT and the Chest X-ray Images Classification
The contagious and pandemic COVID-19 disease is currently considered as the
main health concern and posed widespread panic across human-beings. It affects
the human respiratory tract and lungs intensely. So that it has imposed
significant threats for premature death. Although, its early diagnosis can play
a vital role in revival phase, the radiography tests with the manual
intervention are a time-consuming process. Time is also limited for such manual
inspecting of numerous patients in the hospitals. Thus, the necessity of
automatic diagnosis on the chest X-ray or the CT images with a high efficient
performance is urgent. Toward this end, we propose a novel method, named as the
ULGFBP-ResNet51 to tackle with the COVID-19 diagnosis in the images. In fact,
this method includes Uniform Local Binary Pattern (ULBP), Gabor Filter (GF),
and ResNet51. According to our results, this method could offer superior
performance in comparison with the other methods, and attain maximum accuracy.Comment: 16 pages, 8 figures, submitted for possible journal publicatio
On protection in federated social computing systems
Nowadays, a user may belong to multiple social computing systems (SCSs) in order to benefit from a variety of services that each SCS may provide. To facilitate the sharing of contents across the system boundary, some SCSs provide a mechanism by which a user may “connect ” his accounts on two SCSs. The effect is that contents from one SCS can now be shared to another SCS. Although such a connection feature delivers clear usability advantages for users, it also generates a host of privacy challenges. A notable challenge is that the access control policy of the SCS from which the content originates may not be honoured by the SCS to which the content migrates, because the latter fails to faithfully replicate the protection model of the former. In this paper we formulate a protection model for a fed-eration of SCSs that support content sharing via account connection. A core feature of the model is that sharable con-tents are protected by access control policies that transcend system boundary — they are enforced even after contents are migrated from one SCS to another. To ensure faith-ful interpretation of access control policies, their evaluation involves querying the protection states of various SCSs, us-ing Secure Multiparty Computation (SMC). An important contribution of this work is that we carefully formulate the conditions under which policy evaluation using SMC does not lead to the leakage of information about the protection states of the SCSs. We also study the computational prob-lem of statically checking if an access control policy can be evaluated without information leakage. Lastly, we identify useful policy idioms
An Efficient Anonymous Authentication Scheme Using Registration List in VANETs
Nowadays, Vehicular Ad hoc Networks (VANETs) are popularly known as they can
reduce traffic and road accidents. These networks need several security
requirements, such as anonymity, data authentication, confidentiality,
traceability and cancellation of offending users, unlinkability, integrity,
undeniability and access control. Authentication is one of the most important
security requirements in these networks. So many authentication schemes have
been proposed up to now. One of the well-known techniques to provide users
authentication in these networks is the authentication based on the smartcard
(ASC). In this paper, we propose an ASC scheme that not only provides necessary
security requirements such as anonymity, traceability and unlinkability in the
VANETs but also is more efficient than the other schemes in the literatures.Comment: 5 pages, 4 figures, Accepted for ICEE202
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