16,050 research outputs found
Proxy Signature Scheme with Effective Revocation Using Bilinear Pairings
We present a proxy signature scheme using bilinear pairings that provides
effective proxy revocation. The scheme uses a binding-blinding technique to
avoid secure channel requirements in the key issuance stage. With this
technique, the signer receives a partial private key from a trusted authority
and unblinds it to get his private key, in turn, overcomes the key escrow
problem which is a constraint in most of the pairing-based proxy signature
schemes. The scheme fulfills the necessary security requirements of proxy
signature and resists other possible threats
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
Marrying European and Domestic Politics? The Marriage Referendum in Croatia and Value-Based Euroscepticism
On 1 December 2013, Croatia voted in a referendum on the constitutional definition of marriage. Whilst recent scholarship highlighted the symbolism nature of the referendum in domestic politics, its European dimension has not been reflected on.Using Leconte’s notion of value-based Euroscepticism this article explores the role of European politics in the marriage referendum, using electoral data at the municipal level. As the analysis demonstrates that the referendum, at least partly, was a proactive attempt to halt the Europeanisation of same-sex marriage, the article also sheds light on local resistance to EU’s homonationalist politics
A Byzantine Fault-Tolerant Ordering Service for the Hyperledger Fabric Blockchain Platform
Hyperledger Fabric (HLF) is a flexible permissioned blockchain platform
designed for business applications beyond the basic digital coin addressed by
Bitcoin and other existing networks. A key property of HLF is its
extensibility, and in particular the support for multiple ordering services for
building the blockchain. Nonetheless, the version 1.0 was launched in early
2017 without an implementation of a Byzantine fault-tolerant (BFT) ordering
service. To overcome this limitation, we designed, implemented, and evaluated a
BFT ordering service for HLF on top of the BFT-SMaRt state machine
replication/consensus library, implementing also optimizations for wide-area
deployment. Our results show that HLF with our ordering service can achieve up
to ten thousand transactions per second and write a transaction irrevocably in
the blockchain in half a second, even with peers spread in different
continents
Small-scale solar magnetic fields
As we resolve ever smaller structures in the solar atmosphere, it has become
clear that magnetism is an important component of those small structures.
Small-scale magnetism holds the key to many poorly understood facets of solar
magnetism on all scales, such as the existence of a local dynamo, chromospheric
heating, and flux emergence, to name a few. Here, we review our knowledge of
small-scale photospheric fields, with particular emphasis on quiet-sun field,
and discuss the implications of several results obtained recently using new
instruments, as well as future prospects in this field of research.Comment: 43 pages, 18 figure
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