Digital transformation in public administration necessitates the search for new mechanisms of interaction between the state and citizens. Blockchain technology, characterized by decentralization, immutability of records, and cryptographic security, is considered a promising tool for enhancing transparency, security, and efficiency in G2C (government-to-citizen) and C2G (citizen-to-government) communication sectors. However, a significant gap exists between the theoretical potential of the technology and the practical outcomes of its implementation, necessitating a systematic analysis of both the opportunities and limitations of blockchain in the public sector. Analysis of scholarly literature and practical case studies on blockchain implementation in the public sector reveals a critical gap between the theoretical promises of the technology and the actual results of its application. The study demonstrates that blockchain fundamentally transforms the nature of trust in the public sphere: institutional trust in state bodies is replaced by technological trust in cryptographic algorithms and system developers. This shift generates new forms of dependency and vulnerability. A critical paradox has been identified: a technology designed to ensure transparency creates a new opacity based on the asymmetry of technical knowledge between developers and ordinary citizens. It has been established that the success of blockchain implementation is determined not so much by technical factors (scalability, energy consumption, interoperability), but rather by the organizational resistance of centralized power structures to the redistribution of control over information, communication, and decision-making processes. This explains why the majority of blockchain projects in G2C and C2G communications remain at the pilot stage. A critical analysis of practical cases indicates that blockchain is not a universal solution and should not be implemented as an end in itself. Its value is determined by its ability to address specific problems more effectively than alternative approaches, considering all associated costs and risks. The future of blockchain in public-citizen communications lies not in a total replacement of existing systems, but in selective, hybrid application where its unique attributes deliver maximum effectiveness in solving problems of data verification, distributed trust, and protection against falsification in G2C and C2G communication processes.