506 research outputs found
Encrypted control for networked systems -- An illustrative introduction and current challenges
Cloud computing and distributed computing are becoming ubiquitous in many
modern control systems such as smart grids, building automation, robot swarms
or intelligent transportation systems. Compared to "isolated" control systems,
the advantages of cloud-based and distributed control systems are, in
particular, resource pooling and outsourcing, rapid scalability, and high
performance. However, these capabilities do not come without risks. In fact,
the involved communication and processing of sensitive data via public networks
and on third-party platforms promote, among other cyberthreats, eavesdropping
and manipulation of data. Encrypted control addresses this security gap and
provides confidentiality of the processed data in the entire control loop. This
paper presents a tutorial-style introduction to this young but emerging field
in the framework of secure control for networked dynamical systems.Comment: The paper is a preprint of an accepted paper in the IEEE Control
Systems Magazin
Reuse It Or Lose It: More Efficient Secure Computation Through Reuse of Encrypted Values
Two-party secure function evaluation (SFE) has become significantly more
feasible, even on resource-constrained devices, because of advances in
server-aided computation systems. However, there are still bottlenecks,
particularly in the input validation stage of a computation. Moreover, SFE
research has not yet devoted sufficient attention to the important problem of
retaining state after a computation has been performed so that expensive
processing does not have to be repeated if a similar computation is done again.
This paper presents PartialGC, an SFE system that allows the reuse of encrypted
values generated during a garbled-circuit computation. We show that using
PartialGC can reduce computation time by as much as 96% and bandwidth by as
much as 98% in comparison with previous outsourcing schemes for secure
computation. We demonstrate the feasibility of our approach with two sets of
experiments, one in which the garbled circuit is evaluated on a mobile device
and one in which it is evaluated on a server. We also use PartialGC to build a
privacy-preserving "friend finder" application for Android. The reuse of
previous inputs to allow stateful evaluation represents a new way of looking at
SFE and further reduces computational barriers.Comment: 20 pages, shorter conference version published in Proceedings of the
2014 ACM SIGSAC Conference on Computer and Communications Security, Pages
582-596, ACM New York, NY, US
Challenges and Opportunities for Next-Generation Manufacturing in Space
With commercial space travel now a reality, the idea that people might spend time on other planets in the future seems to have greater potential. To make this possible, however, there needs to be flexible means for manufacturing in space to enable tooling or resources to be created when needed to handle unexpected situations. Next-generation manufacturing paradigms offer significant potential for the kind of flexibility that might be needed; however, they can result in increases in computation time compared to traditional control methods that could make many of the computing resources already available on earth attractive for use. Furthermore, resilience is a significant focus of next-generation manufacturing strategies, and one way to enable resilience for space manufacturing would be to have backup controllers available on earth. These types of considerations raise questions about remote control and monitoring, as well as privacy of the data involved in such practices, that must be considered. This work provides a perspective on several topics tied to remote control and monitoring for manufacturing in space
Recurring Contingent Service Payment
Fair exchange protocols let two mutually distrustful parties exchange digital data in a way that neither party can cheat. They have various applications such as the exchange of digital items, or the exchange of digital coins and digital services between a buyer and seller. At CCS 2017, two blockchain-based protocols were proposed to support the fair exchange of digital coins and a certain service; namely, "proofs of retrievability" (PoR). In this work, we identify two notable issues of these protocols, (1) waste of the seller's resources, and (2) real-time information leakage. To rectify these issues, we formally define and propose a blockchain-based generic construction called "recurring contingent service payment" (RC-S-P). RC-S-P lets a fair exchange of digital coins and verifiable service occur periodically while ensuring that the buyer cannot waste the seller's resources, and the parties' privacy is preserved. It supports arbitrary verifiable services, such as PoR, or verifiable computation and imposes low on-chain overheads. Also, we present a concrete efficient instantiation of RC-S-P when the verifiable service is PoR. The instantiation is called "recurring contingent PoR payment" (RC-PoR-P). We have implemented RC-PoR-P and analysed its cost. When it deals with a 4-GB outsourced file, a verifier can check a proof in 90 milliseconds, and a dispute between prover and verifier is resolved in 0.1 milliseconds
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