The Difficulty in Scaling Blockchains: A Simple Explanation

A General Difficulty Control Algorithm for Proof-of-Work Based Blockchains

Designing an efficient difficulty control algorithm is an essential problem in Proof-of-Work (PoW) based blockchains because the network hash rate is randomly changing. This paper proposes a general difficulty control algorithm and provides insights for difficulty adjustment rules for PoW based blockchains. The proposed algorithm consists a two-layer neural network. It has low memory cost, meanwhile satisfying the fast-updating and low volatility requirements for difficulty adjustment. Real data from Ethereum are used in the simulations to prove that the proposed algorithm has better performan…

Difficulty Scaling in Proof of Work for Decentralized Problem Solving

We propose DIPS Difficulty-based Incentives for Problem Solving), a simple modification of the Bitcoin proof-of-work algorithm that rewards blockchain miners for solving optimization problems of scientific interest. The result is a blockchain which redirects some of the computational resources invested in hash-based mining towards scientific computation, effectively reducing the amount of energy `wasted' on mining. DIPS builds the solving incentive directly in the proof-of-work by providing a reduction in block hashing difficulty when optimization improvements are found. A key advantage of thi…

Blockchain and Machine Learning for Fraud Detection: A Privacy-Preserving and Adaptive Incentive Based Approach

Financial fraud cases are on the rise even with the current technological advancements. Due to the lack of inter-organization synergy and because of privacy concerns, authentic financial transaction data is rarely available. On the other hand, data-driven technologies like machine learning need authentic data to perform precisely in real-world systems. This study proposes a blockchain and smart contract-based approach to achieve robust Machine Learning (ML) algorithm for e-commerce fraud detection by facilitating inter-organizational collaboration. The proposed method uses blockchain to secure…

最长链攻击：难度调整与时间戳可验证性

Longest-chain Attacks: Difficulty Adjustment and Timestamp Verifiability

研究对手在POW区块链中通过构建替代最长链发动攻击的策略，分析难度调整规则下时间戳可验证性的影响，发现可验证时间戳使攻击困难，频繁调整难度增加脆弱性，为设计提供指导。

POEM: Proof of Entropy Minima

Nakamoto consensus has been incredibly influential in enabling robust blockchain systems, and one of its components is the so-called heaviest chain rule (HCR). Within this rule, the calculation of the weight of the chain tip is performed by adding the difficulty threshold value to the previous total difficulty. Current difficulty based weighting systems do not take the intrinsic block weight into account. This paper studies a new mechanism based on entropy differences, named proof of entropy minima (POEM), which incorporates the intrinsic block weight in a manner that significantly reduces the…

七种许可链系统的端到端性能比较

An End-to-End Performance Comparison of Seven Permissioned Blockchain Systems

本文以可复现的端到端方法评估七种许可链系统在不同参数设置下的性能，揭示了各系统的特性与局限，为区块链性能优化研究奠定基础。