Entre blockchains e exchanges: alocando responsabilidade jurídica à luz do código de defesa do consumidor

Abstract

This study analyzes the legal liability arising from illicit acts in cryptocurrency transactions, focusing on the relationship between blockchains and exchanges under the Brazilian Consumer Protection Code (CDC). The central objective is to understand how Brazilian law can allocate civil liability in cases of failures, frauds, or cyberattacks that undermine the integrity of digital financial operations. The research adopts the deductive method and combines exploratory and bibliographic approaches, including jurisprudential and legislative analysis. First, it examines the structure of blockchains — public and private — and their impact on defining the consumer chain. Then, it addresses strict liability under the CDC and the Mitigated Finalist Theory developed by the Superior Court of Justice, which acknowledges consumer vulnerability in the face of technical complexity and informational asymmetry in the digital environment. The study also considers the application of STJ’s Precedent 479, which establishes financial institutions’ liability for internal risks, by analogy applied to exchanges and crypto-asset platforms. Furthermore, it evaluates the Brazilian regulatory framework for crypto-assets (Law nº 14.478/2022) and the European MiCA Regulation, highlighting the need for flexible regulation that reconciles technological innovation with consumer protection. The conclusion indicates that, although the CDC can be applied to transactions involving blockchains and exchanges, its normative insufficiency demands the creation of specific legislation to ensure legal certainty, integrity, and trust in digital transactions, while fostering economic and technological development.