Blockchain-controlled and location-validated locking systems and methods are described. A method includes maintaining state information for a lock, where the first state of the lock corresponds to an open state and the second to a locked state. The method further includes receiving a current location of a device associated with a person, authorized to change a state of the lock, attempting to change a state of the lock and a current location of the lock. The method further includes receiving a digital signature from the device. The method further includes automatically transmitting a control signal to the lock to change the state of the lock only when the current location of the person is determined to be the same as the current location of the lock and a valid proof of work is performed by a miner associated with a blockchain configured to manage transactions corresponding to the lock.