A locking system uses a lock housing, a lock cylinder for rotation in the lock housing, pins to control the lock cylinder being in unlocked or locked states relative to the lock housing, and a key to control the position of the pins. The system further includes a slider or lock bar within the lock housing. The slider moves relative to the lock cylinder and the lock housing between (i) a cylinder locking position blocking rotation of the lock cylinder relative to the lock housing so as to isolate the pins from the torque applied to the lock cylinder while allowing the pins to be displaced between the locked and unlocked positions thereof and (ii) a pin locking position of the slider in which the pins are resisted from movement relative to the lock housing and the lock cylinder while rotation of the lock cylinder is uninhibited by the slider.