1,084 research outputs found
A Flexible Network Approach to Privacy of Blockchain Transactions
For preserving privacy, blockchains can be equipped with dedicated mechanisms
to anonymize participants. However, these mechanism often take only the
abstraction layer of blockchains into account whereas observations of the
underlying network traffic can reveal the originator of a transaction request.
Previous solutions either provide topological privacy that can be broken by
attackers controlling a large number of nodes, or offer strong and
cryptographic privacy but are inefficient up to practical unusability. Further,
there is no flexible way to trade privacy against efficiency to adjust to
practical needs. We propose a novel approach that combines existing mechanisms
to have quantifiable and adjustable cryptographic privacy which is further
improved by augmented statistical measures that prevent frequent attacks with
lower resources. This approach achieves flexibility for privacy and efficency
requirements of different blockchain use cases.Comment: 6 pages, 2018 IEEE 38th International Conference on Distributed
Computing Systems (ICDCS
Blockchain security and applications
Cryptocurrencies, such as Bitcoin and Ethereum, have proven to be highly successful. In a cryptocurrency system, transactions and ownership data are stored digitally in a ledger that uses blockchain technology. This technology has the potential to revolutionize the future of financial transactions and decentralized applications. Blockchains have a layered architecture that enables their unique method of authenticating transactions. In this research, we examine three layers, each with its own distinct functionality: the network layer, consensus layer, and application layer. The network layer is responsible for exchanging data via a peer-to-peer (P2P) network. In this work, we present a practical yet secure network design. We also study the security and performance of the network and how it affects the overall security and performance of blockchain systems. The consensus layer is in charge of generating and ordering the blocks, as well as guaranteeing that everyone agrees. We study the existing Proof-of-stake (PoS) protocols, which follow a single-extension design framework. We present an impossibility result showing that those single-extension protocols cannot achieve standard security properties (e.g., common prefix) and the best possible unpredictability if the honest players control less than 73\% stake. To overcome this, we propose a new multi-extension design framework. The application layer consists of programs (e.g., smart contracts) that users can use to build decentralized applications. We construct a protocol on the application layer to enhance the security of federated learning
Statistical privacy-preserving message dissemination for peer-to-peer networks
Concerns for the privacy of communication is widely discussed in research and
overall society. For the public financial infrastructure of blockchains, this
discussion encompasses the privacy of transaction data and its broadcasting
throughout the network. To tackle this problem, we transform a discrete-time
protocol for contact networks over infinite trees into a computer network
protocol for peer-to-peer networks. Peer-to-peer networks are modeled as
organically growing graphs. We show that the distribution of shortest paths in
such a network can be modeled using a normal distribution
We determine statistical estimators for
via multivariate models. The model behaves logarithmic over the
number of nodes n and proportional to an inverse exponential over the number of
added edges k. These results facilitate the computation of optimal forwarding
probabilities during the dissemination phase for optimal privacy in a limited
information environment.Comment: 6 figures, 19 pages, single colum
Using Distributed Ledger Technologies in VANETs to Achieve Trusted Intelligent Transportation Systems
With the recent advancements in the networking realm of computers as well as achieving real-time communication between devices over the Internet, IoT (Internet of Things) devices have been on the rise; collecting, sharing, and exchanging data with other connected devices or databases online, enabling all sorts of communications and operations without the need for human intervention, oversight, or control. This has caused more computer-based systems to get integrated into the physical world, inching us closer towards developing smart cities.
The automotive industry, alongside other software developers and technology companies have been at the forefront of this advancement towards achieving smart cities. Currently, transportation networks need to be revamped to utilize the massive amounts of data being generated by the public’s vehicle’s on-board devices, as well as other integrated sensors on public transit systems, local roads, and highways. This will create an interconnected ecosystem that can be leveraged to improve traffic efficiency and reliability. Currently, Vehicular Ad-hoc Networks (VANETs) such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-grid (V2G) communications, all play a major role in supporting road safety, traffic efficiency, and energy savings.
To protect these devices and the networks they form from being targets of cyber-related attacks, this paper presents ideas on how to leverage distributed ledger technologies (DLT) to establish secure communication between vehicles that is decentralized, trustless, and immutable. Incorporating IOTA’s protocols, as well as utilizing Ethereum’s smart contracts functionality and application concepts with VANETs, all interoperating with Hyperledger’s Fabric framework, several novel ideas can be implemented to improve traffic safety and efficiency. Such a modular design also opens up the possibility to further investigate use cases of the blockchain and distributed ledger technologies in creating a decentralized intelligent transportation system (ITS)
A Systems Approach to Minimize Wasted Work in Blockchains
Blockchain systems and distributed ledgers are getting increasing attention since the
release of Bitcoin. Everyday they make headlines in the news involving economists,
scientists, and technologists. The technology invented by Satoshi Nakamoto gave to the
world a quantum leap in the fields of distributed systems and digital currencies. Even
so, there are still some problems regarding the architecture in most existing blockchain
systems.
One of the main challenges in these systems is the structure of the network topology
and how peers disseminate messages between them, this leads to problems regarding the
system scalability and the efficiency of the transaction and blocks propagation, wasting
computational power, energy and network resources.
In this work we propose a novel solution to tackle these limitations. We propose
the design of membership and message dissemination protocols, based on the state-ofart,
that will boost the efficiency of the overlay network that support the interactions
between miners, reducing the number of exchanged messages and the used bandwidth.
This solution also reduces the computational power and energy consumed across all
nodes in the network, since the nodes avoid to process redundant network messages, and,
becoming aware of mined blocks faster, avoid to perform computations over an outdated
chain configuration
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