A system includes a processor, a storage medium, a data file, blockchain application, a lock assembly, and a digital key. The data file is stored in the storage medium, and is applied by the blockchain application. The data file includes a plurality of linked blocks, each including a respective transaction data of a plurality of transaction data. Each one of the plurality of transaction data includes a respective event and a time stamp. The blockchain application is stored in the storage medium, executed by the processor, and is configured to output an authorization based on a current grant event of a transaction data of the plurality of transaction data. The digital key is adapted to operate the lock assembly, wherein at least one of the lock assembly and the digital key is configured to receive the authorization in order for the digital key to operate the lock assembly.