Аннотация
The article examines the problem of ensuring the integrity, confidentiality and verifiability of personal data in the context of the growth of digital services and an increase in the number of cyber incidents. The relevance of the study is due to the need to increase trust in government and corporate information systems, especially when processing biometric data. The purpose of the work is to develop and justify the architecture of a blockchain platform for the secure storage and processing of personal data based on an on-chain/off-chain hybrid model. The research methodology includes a systematic analysis of data protection requirements, the design of an information system architecture, the use of cryptographic methods (SHA-256, AES-256) and experimental verification of the implemented prototype. The proposed architecture assumes the storage of personal data in an internal secure storage (off-chain), whereas only hash values and service metadata are recorded in the blockchain journal (on-chain), ensuring the immutability and traceability of operations. As part of the work, a prototype system was implemented with access rights differentiation, mechanisms for single-time fixation of critical attributes (IIN and biometric document), control of block immutability and a procedure for detecting data substitution attempts. The experimental verification confirmed the platform's ability to detect unauthorized changes both in files and in the block log, while maintaining the ability to adjust non-critical fields. The results demonstrate that the hybrid blockchain architecture provides a balance between performance, scalability and a high level of trust in personal data processing and can be used to modernize information systems of government and corporate structures.