This document proposes a blockchain-based cyber security system for data transfer using fiscal devices like GPRS terminals. It discusses how blockchain can improve data security by making data tampering nearly impossible through decentralization and encryption of transaction records across many nodes. The system would break data into encrypted blocks, distribute copies across nodes, and validate transfers using smart contracts to securely record transfers with reduced storage needs. This provides an auditable record of transfers that improves traceability and security over centralized systems.