32,857 research outputs found
RHyTHM: A Randomized Hybrid Scheme To Hide in the Mobile Crowd
Any on-demand pseudonym acquisition strategy is problematic should the
connectivity to the credential management infrastructure be intermittent. If a
vehicle runs out of pseudonyms with no connectivity to refill its pseudonym
pool, one solution is the on-the-fly generation of pseudonyms, e.g., leveraging
anonymous authentication. However, such a vehicle would stand out in the crowd:
one can simply distinguish pseudonyms, thus signed messages, based on the
pseudonym issuer signature, link them and track the vehicle. To address this
challenge, we propose a randomized hybrid scheme, RHyTHM, to enable vehicles to
remain operational when disconnected without compromising privacy: vehicles
with valid pseudonyms help others to enhance their privacy by randomly joining
them in using on-the-fly self-certified pseudonyms along with aligned
lifetimes. This way, the privacy of disconnected users is enhanced with a
reasonable computational overhead.Comment: 4 pages, 4 figures, IEEE Vehicular Networking Conference (VNC),
November 27-29, 2017, Torino, Ital
FastPay: High-Performance Byzantine Fault Tolerant Settlement
FastPay allows a set of distributed authorities, some of which are Byzantine,
to maintain a high-integrity and availability settlement system for pre-funded
payments. It can be used to settle payments in a native unit of value
(crypto-currency), or as a financial side-infrastructure to support retail
payments in fiat currencies. FastPay is based on Byzantine Consistent Broadcast
as its core primitive, foregoing the expenses of full atomic commit channels
(consensus). The resulting system has low-latency for both confirmation and
payment finality. Remarkably, each authority can be sharded across many
machines to allow unbounded horizontal scalability. Our experiments demonstrate
intra-continental confirmation latency of less than 100ms, making FastPay
applicable to point of sale payments. In laboratory environments, we achieve
over 80,000 transactions per second with 20 authorities---surpassing the
requirements of current retail card payment networks, while significantly
increasing their robustness
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