113 research outputs found
Towards Secure Blockchain-enabled Internet of Vehicles: Optimizing Consensus Management Using Reputation and Contract Theory
In Internet of Vehicles (IoV), data sharing among vehicles is essential to
improve driving safety and enhance vehicular services. To ensure data sharing
security and traceability, highefficiency Delegated Proof-of-Stake consensus
scheme as a hard security solution is utilized to establish blockchain-enabled
IoV (BIoV). However, as miners are selected from miner candidates by
stake-based voting, it is difficult to defend against voting collusion between
the candidates and compromised high-stake vehicles, which introduces serious
security challenges to the BIoV. To address such challenges, we propose a soft
security enhancement solution including two stages: (i) miner selection and
(ii) block verification. In the first stage, a reputation-based voting scheme
for the blockchain is proposed to ensure secure miner selection. This scheme
evaluates candidates' reputation by using both historical interactions and
recommended opinions from other vehicles. The candidates with high reputation
are selected to be active miners and standby miners. In the second stage, to
prevent internal collusion among the active miners, a newly generated block is
further verified and audited by the standby miners. To incentivize the standby
miners to participate in block verification, we formulate interactions between
the active miners and the standby miners by using contract theory, which takes
block verification security and delay into consideration. Numerical results
based on a real-world dataset indicate that our schemes are secure and
efficient for data sharing in BIoV.Comment: 12 pages, submitted for possible journal publicatio
An Analysis of Transaction Handling in Bitcoin
Bitcoin has become the leading cryptocurrency system, but the limit on its
transaction processing capacity has resulted in increased transaction fees and
delayed transaction confirmation. As such, it is pertinent to understand and
probably predict how transactions are handled by Bitcoin such that a user may
adapt the transaction requests and a miner may adjust the block generation
strategy and/or the mining pool to join. To this aim, the present paper
introduces results from an analysis of transaction handling in Bitcoin.
Specifically, the analysis consists of two-part. The first part is an
exploratory data analysis revealing key characteristics in Bitcoin transaction
handling. The second part is a predictability analysis intended to provide
insights on transaction handling such as (i) transaction confirmation time,
(ii) block attributes, and (iii) who has created the block. The result shows
that some models do reasonably well for (ii), but surprisingly not for (i) or
(iii)
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