997 research outputs found
Scalable Open-Vote Network on Ethereum
McCorry et al. (Financial Cryptography 2017) presented the first implementation of a decentralized self-tallying voting protocol on Ethereum. However, their implementation did not scale beyond 40 voters since all the computations were performed on the smart contract. In this paper, we tackle this problem by delegating the bulk computations to an off-chain untrusted administrator in a verifiable manner. Specifically, the administrator tallies the votes off-chain and publishes a Merkle tree that encodes the tallying computation trace. Then, the administrator submits the Merkle tree root and the tally result to the smart contract. Subsequently, the smart contract transits to an intermediate phase where at least a single honest voter can contend the administrator\u27s claimed result if it was not computed correctly. Then, in the worst case, the smart contract verifies the dispute at the cost of an elliptic curve point addition and scalar multiplication, and two Merkle proofs of membership which are logarithmic in the number of voters. This allows our protocol to achieve higher scalability without sacrificing the public verifiability or voters\u27 privacy. To assess our protocol, we implemented an open-source prototype on Ethereum and carried out multiple experiments for different numbers of voters.
The results of our implementation confirm the scalability and efficiency of our proposed solution which does not exceed the current block gas limit for any practical number of voters
Combining Blockchain and Swarm Robotics to Deploy Surveillance Missions
Current swarm robotics systems are not utilized as frequently in surveillance missions due to the limitations of the existing distributed systems\u27 designs. The main limitation of swarm robotics is the absence of a framework for robots to be self-governing, secure, and scalable. As of today, a swarm of robots is not able to communicate and perform tasks in transparent and autonomous ways. Many believe blockchain is the imminent future of distributed autonomous systems. A blockchain is a system of computers that stores and distributes data among all participants. Every single participant is a validator and protector of the data in the blockchain system. The data cannot be modified since all participants are storing and watching the same records. In this thesis, we will focus on blockchain applications in swarm robotics using Ethereum smart contracts because blockchain can make a swarm globally connected and secure. A decentralized application (DApp) is used to deploy surveillance missions. After mission deployment, the swarm uses blockchain to communicate and make decisions on appropriate tasks within Ethereum private networks. We set a test swarm robotics system and evaluate the blockchain for its performance, scalability, recoverability, and responsiveness. We conclude that, although blockchain enables a swarm to be globally connected and secure, there are performance limitations that can become a critical issue
Chainspace: A Sharded Smart Contracts Platform
Chainspace is a decentralized infrastructure, known as a distributed ledger,
that supports user defined smart contracts and executes user-supplied
transactions on their objects. The correct execution of smart contract
transactions is verifiable by all. The system is scalable, by sharding state
and the execution of transactions, and using S-BAC, a distributed commit
protocol, to guarantee consistency. Chainspace is secure against subsets of
nodes trying to compromise its integrity or availability properties through
Byzantine Fault Tolerance (BFT), and extremely high-auditability,
non-repudiation and `blockchain' techniques. Even when BFT fails, auditing
mechanisms are in place to trace malicious participants. We present the design,
rationale, and details of Chainspace; we argue through evaluating an
implementation of the system about its scaling and other features; we
illustrate a number of privacy-friendly smart contracts for smart metering,
polling and banking and measure their performance
IDMoB: IoT Data Marketplace on Blockchain
Today, Internet of Things (IoT) devices are the powerhouse of data generation
with their ever-increasing numbers and widespread penetration. Similarly,
artificial intelligence (AI) and machine learning (ML) solutions are getting
integrated to all kinds of services, making products significantly more
"smarter". The centerpiece of these technologies is "data". IoT device vendors
should be able keep up with the increased throughput and come up with new
business models. On the other hand, AI/ML solutions will produce better results
if training data is diverse and plentiful.
In this paper, we propose a blockchain-based, decentralized and trustless
data marketplace where IoT device vendors and AI/ML solution providers may
interact and collaborate. By facilitating a transparent data exchange platform,
access to consented data will be democratized and the variety of services
targeting end-users will increase. Proposed data marketplace is implemented as
a smart contract on Ethereum blockchain and Swarm is used as the distributed
storage platform.Comment: Presented at Crypto Valley Conference on Blockchain Technology (CVCBT
2018), 20-22 June 2018 - published version may diffe
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