MODEL OF A DOCUMENT MANAGEMENT SYSTEM WITH A CRYPTOGRAPHICALLY VERIFIABLE DOCUMENT STATE CHAIN

Abstract

This paper develops a document management system model intended for environments in which the integrity of document history, control of the document lifecycle, and the possibility of independent verification of performed operations are critically important. The relevance of the study is determined by the fact that traditional electronic document management systems mainly rely on centralized event logs and application logic, which does not eliminate the risks of retrospective modification of document history and a reduction in its evidential value. The aim of the work is to construct a document management system model in which the integrity of document history is ensured through a cryptographically verifiable chain of document states and the recording of evidential event attributes in a permissioned distributed ledger. The proposed model combines architectural and formal levels of system representation. At the architectural level, the user, application, evidential, and content layers are distinguished. At the formal level, a document is represented as a sequence of cryptographically linked states, in which each new state contains the state hash, metadata, timestamp, content hash, and a reference to the previous state, thus ensuring the integrity and traceability of the entire document history. To implement the evidential layer, a smart contract for registering document states and a permissioned distributed ledger based on Hyperledger Besu are used. Experimental validation of the model was carried out on a local testbed using the QBFT consensus mechanism, external storage, and software modules for generating and fully verifying document history. The experimental results confirmed the ability of the model to detect retrospective changes in content, metadata, signatures, and temporal attributes, to localize the first compromised state, and to provide near-linear growth in full verification time as the length of the state chain increases. Comparative evaluation against centralized logging demonstrated the advantage of the proposed approach in terms of tamper detection, localization of violations, and independent verifiability of results. The practical significance of the work lies in the possibility of using the proposed model as a basis for building corporate document management systems.