Corpus ID: 3947910

Sharding PoW-based Blockchains via Proofs of Knowledge

  title={Sharding PoW-based Blockchains via Proofs of Knowledge},
  author={Frederik Armknecht and J. Bohli and Ghassan O. Karame and Wenting Li},
  journal={IACR Cryptol. ePrint Arch.},
Blockchains based on proofs of work (PoW) currently account for more than 90% of the total market capitalization of existing digital cryptocurrencies. [...] Key Result We implemented EWoK and integrated it within commonly used mining protocols, such as GetBlockTemplate and Stratum mining; our results show that EWoK can be easily integrated within existing mining pool protocols and does not impair the mining efficiency.Expand
PoNW: A Secure and Scalable Proof-of-Notarized-Work Based Consensus Mechanism
Results from the security analysis have shown that the proposed consensus algorithm ensures forks cannot occur, and it remains secure and consistent even amid numerous attacks, solving the issue of scalability. Expand
Audita: A Blockchain-based Auditing Framework for Off-chain Storage
Audita is a solution prototype that allows data to be reliably stored while simultaneously being secured, with tamper-evident auditability, via blockchain, and is a flexible solution that assures data protection and solves challenges such as scalability and privacy. Expand
What is a Blockchain? A Definition to Clarify the Role of the Blockchain in the Internet of Things
This position paper elaborates on the theory of distributed systems to advance a clear definition of blockchain, and indicates a feasible role of the blockchain for the IoT: myriads of local, IoT transactions can be aggregated off-chain and then be successfully recorded on an external blockchain as a means of public accountability when required. Expand


On the Security and Performance of Proof of Work Blockchains
This paper introduces a novel quantitative framework to analyse the security and performance implications of various consensus and network parameters of PoW blockchains and devise optimal adversarial strategies for double-spending and selfish mining while taking into account real world constraints. Expand
Blockchain-Free Cryptocurrencies : A Framework for Truly Decentralised Fast Transactions
The “blockchain” distributed ledger pioneered by Bitcoin is effective at preventing double-spending, but inherently attracts (1) “user cartels” and (2) incompressible delays, as a result of linearExpand
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This paper implements Bitcoin-NG, a new blockchain protocol designed to scale, which is Byzantine fault tolerant, is robust to extreme churn, and shares the same trust model obviating qualitative changes to the ecosystem. Expand
Bitcoin and Blockchain Security
There is a lot of buzz about Bitcoin and Blockchain lately, our expert authors will help to answer some imperative questions about the security involved in this new digital asset and ledger. ThisExpand
The Quest for Scalable Blockchain Fabric: Proof-of-Work vs. BFT Replication
  • M. Vukolic
  • Engineering, Computer Science
  • iNetSeC
  • 2015
In the early days of Bitcoin, the performance of its probabilistic proof-of-work (PoW) based consensus fabric, also known as blockchain, was not a major issue, and Bitcoin became a success story, despite its consensus latencies on the order of an hour and the theoretical peak throughput of only up to 7 transactions per second. Expand
SPECTRE: A Fast and Scalable Cryptocurrency Protocol
SPECTRE is presented, a new protocol for the consensus core of crypto-currencies that remains secure even under high throughput and fast confirmation times, and can operate at high block creation rates, which implies that its transactions confirm in mere seconds. Expand
Provable data possession at untrusted stores
The model generates probabilistic proofs of possession by sampling random sets of blocks from the server, which drastically reduces I/O costs and the overhead at the server is low (or even constant), as opposed to linear in the size of the data. Expand
Retricoin: Bitcoin based on compact proofs of retrievability
Retricoin is a scheme called Retricoin which replaces the heavy computational proof-of-work of Bitcoin by proofs of retrievability that have practical benefits. Expand
Compact Proofs of Retrievability
The first proof-of-retrievability schemes with full proofs of security against arbitrary adversaries in the strongest model, that of Juels and Kaliski, are given. Expand
Enhancing Bitcoin Security and Performance with Strong Consistency via Collective Signing
This paper introduces ByzCoin, a novel Byzantine consensus protocol that leverages scalable collective signing to commit Bitcoin transactions irreversibly within seconds, and achieves a throughput higher than PayPal currently handles, with a confirmation latency of 15-20 seconds. Expand