A method and a system for transmitting enforceable instructions in a positive train control (PTC) system includes receiving, by a cyclic redundancy check (CRC) calculator, at least one enforceable instruction from railroad systems. The CRC calculator calculates at least one enforceable instruction CRC based at least partly on the at least one enforceable instruction and transmits the at least one enforceable instruction CRC to a back office server of the PTC system and/or an on-board system of a locomotive. Methods for cyclic redundancy check (CRC) hazard mitigation in a positive train control (PTC) system and verifying enforceable instruction data on-board a train are also disclosed.