Atomic Transfer Graphs: Secure-by-design Protocols for Heterogeneous Blockchain Ecosystems

2025-01-29

AI Summary

Existing cross-chain atomic transfer protocols lack generality, security, and efficiency across heterogeneous blockchains. Method: This paper introduces the Atomic Transfer Graph (ATG) to uniformly model diverse cross-chain scenarios—including payment channel networks and multi-asset swaps—enabling their first structured representation. It designs Conditional Time-Locked Contracts (CTLCs) as lightweight, portable smart contract primitives and constructs the first generic, provably secure cross-chain protocol framework. Contribution/Results: The framework supports deployment on script-restricted chains (e.g., Bitcoin), undergoes formal security verification, and achieves performance comparable to or better than existing ad-hoc solutions. It significantly advances cross-chain protocol design by simultaneously enhancing security, generality, and practical deployability.

Technology Category

• Multiagent Systems: Mechanism Design
• Application Domains: Security
• Game Theory and Economic Paradigms: Mechanism Design

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Economics, Online Markets and Human Computation: Economic aspects of blockchain and cryptocurrencies
• Systems and Infrastructure for Web, Mobile and WoT: Web applications in cross-disciplinary domains and verticals such as mixed reality, smart cities, and digital health

Abstract

The heterogeneity of the blockchain landscape has motivated the design of blockchain protocols tailored to specific blockchains and applications that, hence, require custom security proofs. We observe that many blockchain protocols share common security and functionality goals, which can be captured by an atomic transfer graph (ATG) describing the structure of desired transfers. Based on this observation, we contribute a framework for generating secure-by-design protocols that realize these goals. The resulting protocols build upon Conditional Timelock Contracts (CTLCs), a novel minimal smart contract functionality that can be implemented in a large variety of cryptocurrencies with a restricted scripting language (e.g., Bitcoin), and payment channels. We show how ATGs, in addition to enabling novel applications, capture the security and functionality goals of existing applications, including many examples from payment channel networks and complex multi-party cross-currency swaps among Ethereum-style cryptocurrencies. Our framework is the first to provide generic and provably secure protocols for all these use cases while matching or improving the performance of existing use-case-specific protocols.

Problem

• Blockchain Security
• Rule Design
• Efficiency Optimization

Innovation

• Atomic Transaction Graphs
• Conditional Time Lock Contracts
• Cross-Blockchain Security