The article presents a comparative analysis of the main Layer 2 scaling technologies in blockchain systems: Rollups (Optimistic and ZK), Sidechains, and the Lightning Network. The relevance of the study is driven by the fundamental scalability problem of Layer 1 blockchains, which limits their throughput and increases transaction costs. The novelty lies in the systematization and comparison of these technologies using a multi-criteria model that includes security, performance, decentralization, and economic efficiency. The study describes the architectural principles of each solution and examines their security mechanisms and trust models. Special attention is paid to the trade-offs between inheriting security from the base network and operational independence. The work aims to identify the strengths and weaknesses of each approach to determine their optimal application scenarios. To achieve this, methods of comparative analysis, systematization, and analysis of the scholarly literature are employed. Fundamental and contemporary research in the field of L2 solutions is reviewed. The conclusion presents the key findings and proposes a framework for selecting a technology depending on the requirements of a decentralized application. The article will be useful for blockchain system developers, researchers, and architects of decentralized applications.

blockchain, Layer 2, scalability, Rollups, ZK-Rollups, Optimistic Rollups, Sidechains, Lightning Network, throughput, transaction fees

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