Embodiments of secure wound therapy systems and methods for operating the systems are disclosed. In some embodiments, the apparatus includes a pressure source, a user interface, and a locking mechanism. The locking mechanism can be in one of at least two states, the at least two states including a first state in which the locking mechanism physically prevents user adjustment of one or more operational parameters with the user interface and a second state in which the locking mechanism does not physically prevent user adjustment of the one or more operational parameters with the user interface. The locking mechanism can include an authentication key and a receiver configured to receive an authentication input, which may be compared to the authentication key. Providing a sufficiently matching authentication input can transition the locking mechanism from the first state to the second state, permitting adjustments to the one or more operational parameters.