When Can You Trust Bitcoin? Value-Dependent Block Confirmation to Determine Transaction Finalit

2025-11-19

AI Summary

Bitcoin transaction finality is vulnerable to reversal due to blockchain forks, and the conventional fixed six-block confirmation rule fails to balance security and efficiency. This paper proposes a value-aware dynamic confirmation model. First, it develops a network-latency-driven fork probability model, empirically calibrated using on-chain data and Monte Carlo simulations to quantify the relationship between confirmation depth and reversal risk. Second, it introduces prospect theory into the confirmation mechanism—marking the first such application—to jointly incorporate user risk preferences and transaction value into the decision framework. Finally, it establishes a computable mapping among transaction amount, user-specific risk tolerance, and optimal confirmation depth. Experimental evaluation demonstrates that the model significantly enhances security for high-value transactions while reducing confirmation latency for low-value ones, enabling risk-adaptive and personalized finality assessment.

Technology Category

• Game Theory and Economic Paradigms: Mechanism Design
• Multiagent Systems: Mechanism Design
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust

Application Category

• User Modeling, Personalization and Recommendation: Attacks and countermeasures in recommendation systems
• Security and Privacy: Blockchains and distributed ledgers
• Economics, Online Markets and Human Computation: Economic aspects of blockchain and cryptocurrencies

Abstract

We study financial transaction confirmation finality in Bitcoin as a function of transaction amount and user risk tolerance. A transaction is recorded in a block on a blockchain. However, a transaction may be revoked due to a fork in the blockchain, the odds of which decrease over time but never reach zero. Therefore, a transaction is considered confirmed if its block is sufficiently deep in the blockchain. This depth is usually set empirically at some fixed number such as six blocks. We analyze forks under varying network delays in simulation and actual Bitcoin data. Based on this analysis, we establish a relationship between block depth and the probability of confirmation revocation due to a fork. We use prospect theory to relate transaction confirmation probability to transaction amount and user risk tolerance.

Problem

• Determining Bitcoin transaction finality based on value and risk
• Analyzing blockchain fork probabilities under varying network conditions
• Relating confirmation probability to transaction amount using prospect theory

Innovation

• Value-dependent block confirmation for Bitcoin
• Simulation and data analysis of network forks
• Prospect theory linking risk to transaction amount