Abstract: A code locking mechanism that transmits information between a key and a locking mechanism secured against interception misuse, but flexible with respect to original equipment, replacement parts, and emergency functions, is obtained if the key code is, in each case, cryptographically encoded through a hardware encoder. When the locking mechanism is first operated, a control element, inductively coupled to a locking mechanism read-write unit with a new key once and in a non-overwritable manner, transmits an indent number to the object memory. Object-specific identity data are also stored in the control element. With the latter, a key number from a key register of the control element is combined with the key code to read the latter together with a roll-in random code into the set of first still-neutral keys and into the object memory. Thus, a key is valid only if the object-specific identity data are taken into account in its key code.