Secure-printing specialist De La Rue is researching techniques that could build active anti-counterfeiting checks into banknotes and medicine labels, using the energy harvested from radio communications to power them.
Speaking at the Printed Electronics conference in Berlin earlier this week (1-2 April), De La Rue head of ideas Philip Cooper explained that, "In security products we are in a war against organisations and counterfeiters who copy everything we hold valuable. We have to go for techniques that are harder and harder to copy. Printed electronics can be a platform technology. The technology is upgradable, so that if it gets attacked at one level we can upgrade it."
Cooper said the overall concept would use printed logic circuits to compute a value or message – possibly unique to the individual banknote or label – and show it on the note itself using an integrated display, possibly based on the OLED (organic light-emitting diode) technology already used in mobile phones. "Uniqueness can be exploited," added Cooper. "It can make the system very hard to copy."
One of the key problems with the approach is providing power. Although printed battery technology exists, Cooper said: "They are too costly or they do not last long. The system needs to be ultra-low cost - less than half a cent. It is challenging, but it's not impossible."
Instead, Cooper's plan is to use the radio energy used to drive passive RFID tags and contactless smartcards to drive the circuitry: "There is enough energy there to provide what we need, around 1-2mW."
To check a note, the user would trigger the circuit using the NFC reader in a phone or a dedicated scanner.
Cooper said for printed electronics to move into secure notes and labels, the technology needs to be improved, particularly with the reliability of the printed materials and the number of steps it takes to produce a working system.
"There are problems. Many users, including us, get quite fed up with the hype with not a lot to show for it," Cooper continued. "For us the credibility gap is too large at the moment. If I go to the board and ask for funding they will ask 'what are the risks?' I would say they are quite high."