This involves the use of electricity conducting inks to produce office stamps and seals. The electric resistance of the ink pigments are designed to be unique to each document that is stamped so that when the documents are stamped, the resistance of the conducting ink changes. This change can be used to determine the order in which the documents are stamped. Since the stamp keeps track of the number of times it used, it can help the authorities to detect unauthorized use of the stamp and cancel the validity of the concerned document.
The serial number of the stamp can be checked by measuring the resistance of the stamp on the document. The serial number of the stamp can be checked on an online database to verify the authenticity of the stamp. In cases where the stamp was used without authorization, the stamp's corresponding serial number can be deleted from the database or specified as a forgery.
An advantage of this system of stamps is that there is a specific number times you can use the stamp. The stamp can be made invalid if it should get stolen while the documents that were stamped with it before it got stolen will always be valid. This type of stamp will add an extra hurdle for forgers to deal with. The system can also be used to invalidate expired credentials or credentials that were gotten fraudulently. The main problem this type of stamp poses to forgers is that there is a fixed number of possible stamps and the order of the stamp's use is recorded. It is not something that an official with a high clearance can easily change from their computer. In the case where an organisation's member or official helps to create forgeries, the fault will be easy to trace back to them.