THE EVOLUTION OF SMART CONTRACTS IN WEB3 AND DEFI SYSTEMS: ARCHITECTURAL TRANSFORMATION OF SECURITY THREATS AND PROSPECTS FOR COMPREHENSIVE PROTECTION

DOI: 10.31673/2409-7292.2026.011651

Abstract

The article studies the evolution of smart contracts as a key functional component of Web3 architecture and decentralized
financial environments. It is established that smart contracts have undergone a consistent transformation - from localized
software mechanisms for executing transactions to complex multi-contract protocol structures capable of implementing
financial, coordination and management functions in the absence of centralized intermediaries. The paper analyzes the
architectural features of smart contract execution in various Web3 platforms, in particular in the Ethereum, Solana and Polkadot
ecosystems, and also reveals the role of compositionality and inter-contract interaction in the formation of modern DeFi
ecosystems. The evolution of scientific and technical approaches to interpreting the concept of a smart contract is analyzed. The
author's definition of a smart contract is proposed. An analysis of the transformation of smart contract security threats is
conducted, covering protocol and economic attack mechanisms, in particular front-running, oracle manipulation, and maximum
value extraction practices. Modern approaches to ensuring the security of smart contracts are summarized, including methods
of formal verification, symbolic execution, automated analysis, and integration of security mechanisms into their development
lifecycle. The results obtained justify the need to transition from fragmented audit tools to a comprehensive, methodologically
consistent approach to ensuring the security of smart contracts, which takes into account the evolutionary complexity of
decentralized systems, the multi-level architecture of Web3 platforms, and the economic context of the functioning of DeFi
protocols. The proposed conclusions create a basis for further development of integrated models and methodologies for ensuring
the security of smart contracts in decentralized environments.
Keywords: smart contracts, Web3 systems, DeFi systems, transformation of security threats, comprehensive protection.

References
1. Szabo N. Formalizing and securing relationships on public networks // First Monday. 1997. Vol. 2, no. 9. URL:
https://firstmonday.org/ojs/index.php/fm/article/view/548.
2. Smart contract // Glossary / National Institute of Standards and Technology (NIST). URL:
https://csrc.nist.gov/glossary/term/smart_contract.
3. Buterin V. Ethereum: a next-generation smart contract and decentralized application platform: white paper.
2014. URL: https://ethereum.org/whitepaper.
4. Clack C. D., Bakshi V. A., Braine L. Smart contract templates: foundations, design landscape and research
directions // arXiv. 2016. arXiv:1608.00771. URL: https://arxiv.org/abs/1608.00771.
5. Tolmach P., Li Y., Lin S.-W., Liu Y., Li Z. A survey of smart contract formal specification and verification //
ACM Computing Surveys. 2020. Vol. 54, no. 7. Art. 148. DOI: 10.1145/3399438.
6. Schär F. Decentralized finance: on blockchain- and smart contract-based financial markets // Federal Reserve
Bank of St. Louis Review. 2021. Vol. 103, no. 2. P. 153–174. DOI: 10.20955/r.103.153-174.
7. Smart contracts security: threat landscape and risk assessment / European Union Agency for Cybersecurity
(ENISA). 2021. URL: https://www.enisa.europa.eu/publications.
8. Chu H., Zhang Z., Chen J., Wang X., Li Z. A survey on smart contract vulnerabilities // Information and
Software Technology. 2023. Vol. 155. Art. 107097. DOI: 10.1016/j.infsof.2022.107097.
9. Yakovenko A. Solana: a new architecture for a high performance blockchain: white paper. Version 0.8.13.
Solana Labs, 2020. 32 p. URL: https://solana.com/solana-whitepaper.pdf.
10. Kao H.-T., Chitra T., Chiang R., Morrow J. An analysis of the market risk to participants in the Compound
protocol // Proceedings of the Third International Symposium on Foundations and Applications of Blockchain (FAB’20).
Santa Cruz, CA, USA, 2020. P. 1–10. DOI: 10.1145/3380745.3405124.
11. Smart contracts in blockchain systems: architecture, applications and security challenges // Computers. 2025.
Vol. 14, no. 2. Art. 226. URL: https://www.mdpi.com/2073-431X/14/2/226.