The examination of keys (for locks and profile cylinders on the premises as well as keys for other security devices and for vehicles) serves to ascertain whether duplicate keys were made.

Gauge marks indicate that a key was duplicated with a mechanical profile-milling machine. There follows an assessment of the further use of those keys, drawing on the results of serial examinations, experience and input from third parties. On occasion, an EDX system may be used for material analysis, to determine any materials transferred to the key during use.

Initially, the integrity of a set of keys is checked against our comprehensive in-house database. Next, production marks and cuts are compared with those of the manufacturer, and it is determined whether the keys are originals or duplicates.

Keys are also examined for evidence of having been used as sample keys for producing cast duplicates. Any foreign materials transferred are subjected to EDX or infrared analysis. The keys are tested to establish whether they were cut using an electronic or laser-driven profile-milling machine using a non-contact scanner.

All observations gained from these examinations are included in the inspection records and dealt with under the four-eye-principle.


Keys that can be copied

Read-out of cuts

Gauge marks (optical microscope)

Gauge marks (SEM)

Gauge marks on cuts

Surface distortion


If keys have electronic elements, e.g. for deactivating an immobilizer or activating a mechatronical locking cylinder, the electronic parts (as a rule, transponders) are read using specialist equipment. Values obtained are compared to stored data, for example that of manufacturers, to establish the system and integrity.

Should further lock or vehicle-specific data be stored within the elements, these too will be read and compared to manufacturer or user data and the results recorded in the inspection records. If alterations are found, these are examined to determine how they were made. These examinations aim to establish whether the user made these alterations, for example, to enable a crime to be committed or to pretend that a crime was committed, or whether third parties made these alterations in preparation for committing a crime, or to cause any other damage for which an insurer would be liable. Any kind of mechanical alteration of the electronic elements is always analyzed under the stereo-zoom microscope or the scanning electron microscope and recorded with digital photography.


Key read-out data

Reader for transponders

Circuit board with transponder

Key fob with transponder


Car key with transponder