A cable padlock having a thin flexible cable, with a key attached to one cable end and a locking mechanism for receiving and securing the key attached to the other cable end, preferably of a combination or permutation type. The key and locking mechanism are constructed of lightweight materials such as aluminum, providing for a lightweight, compact, and potentially inexpensive padlock. A mechanism for detaching the cable from the locking mechanism by application of a master key is provided to allow an administrator of a facility utilizing a number of the locks to remove each lock without needing to lookup each lock's unique combination. The lock is accordingly useful in prisons, institutions, and other secured facilities where there are concerns that a traditional heavier lock could be used as a makeshift weapon.