Blockchain-based Smart Contracts: A Systematic Mapping Study (1710.06372v1)

Abstract: An appealing feature of blockchain technology is smart contracts. A smart contract is executable code that runs on top of the blockchain to facilitate, execute and enforce an agreement between untrusted parties without the involvement of a trusted third party. In this paper, we conduct a systematic mapping study to collect all research that is relevant to smart contracts from a technical perspective. The aim of doing so is to identify current research topics and open challenges for future studies in smart contract research. We extract 24 papers from different scientific databases. The results show that about two thirds of the papers focus on identifying and tackling smart contract issues. Four key issues are identified, namely, codifying, security, privacy and performance issues. The rest of the papers focuses on smart contract applications or other smart contract related topics. Research gaps that need to be addressed in future studies are provided.

• The paper identifies smart contract research trends, focusing on security vulnerabilities, performance bottlenecks, and difficulties in codifying contracts.
• It categorizes 24 studies, showing that nearly two-thirds address security and privacy concerns with specific countermeasures like vulnerability detection tools.
• The study highlights future research needs in improving scalability, exploring alternative blockchain platforms, and automating contract verification.

Overview of Blockchain-Based Smart Contracts: Systematic Mapping Study

The paper "Blockchain-Based Smart Contracts: A Systematic Mapping Study" by Maher Alharby and Aad van Moorsel explores the technical aspects of smart contracts within the blockchain sphere. Smart contracts, essentially autonomous executable codes on a blockchain, enable parties to facilitate, execute, and enforce agreements without a centralized authority. This paper seeks to identify the core research topics surrounding smart contracts and highlights areas ripe for future inquiry.

Key Findings

The authors meticulously analyzed 24 selected papers from various reputable scientific databases to map current research trends and discern open challenges in smart contract technology. The resulting categorization of literature indicates a predominant focus on security, privacy, and performance issues, as these areas accounted for approximately two-thirds of the reviewed papers. The remaining studies concentrated on applications of smart contracts or other related topics.

Core Research Topics and Challenges

Security and Privacy Concerns

Security concerns, given their potential impact on financially significant contracts, received substantial attention. Issues such as transaction-ordering dependencies, timestamp dependencies, mishandled exceptions, and re-entrancy vulnerabilities are outlined with proposed countermeasures, including tools like 'OYENTE' for vulnerability detection. Notably, the paper discusses privacy issues in smart contracts, particularly regarding transactional and data feed privacy, proposing solutions like the 'Hawk' tool for privacy-preserving contracts, and the 'Town Crier' for authenticated data feeds.

Performance Issues

The paper identifies performance bottlenecks, notably the sequential execution of smart contracts, which potentially impairs transaction scalability. Although parallel execution is suggested, challenges remain for executing dependent contracts simultaneously.

Codifying and Modifiability

Challenges in codifying smart contracts are discussed, emphasizing the difficulty of writing correct contracts, their immutability post-deployment, and the complexity of current procedural languages like Solidity. Proposed methodologies include automation aids and formal verification techniques to improve contract accuracy and efficiency.

Smart Contract Applications

The paper identifies various smart contract applications beyond traditional use cases, including Internet of Things (IoT), e-commerce, and identity management. Ethereum emerges as the dominant platform due to its Turing-complete capabilities facilitating complex contracts, despite discussions on other platforms like NXT and Bitcoin with inherent limitations.

Research Gaps and Future Directions

Several research gaps are pinpointed:

1. Scalability and Performance: Further exploration into enhancing blockchain scalability and performance beyond parallelization remains critical.
2. Alternative Blockchain Platforms: Investigating smart contract deployment on blockchains other than Ethereum, considering different architectures could provide insights into more robust implementations.
3. Proliferation of Applications: The infancy of smart contract technology warrants more application development across sectors to propel adoption and innovation.
4. Criminal Activity Mitigation: Despite highlighting potential for misuse in activities such as key theft or unauthorized document leakage, comprehensive solutions remain undeveloped.
5. Quality of Research: Emphasizing peer-reviewed, high-quality studies can enrich smart contract literature beyond gray literature and blog discourse.

Conclusion

The systematic mapping paper offers a granular understanding of the challenges and scope within smart contract research. By addressing identified gaps, future studies can enhance the robustness, adoption, and utility of smart contracts across diverse applications, thereby reinforcing the blockchain ecosystem's foundational principles of security, transparency, and decentralization. This research contributes meaningfully to the ongoing discourse and provides a platform for targeted advancements in blockchain-based contract technology.