Sandia unveils cryptographic tamper protection

Sandia National Laboratories of the US has developed a new security seal to protect shipments from tampering that is available for licensing.

The SecuritySeal technology, which is based on physical unclonable functions or PUFs, is described as a patented method of tagging and sealing containers or doors. When the microelectronic device is placed on a closed container, any attempt to open it is detected cryptographically.

PUFs are the small defects that are part of any manufacturing process. They are slight variations in thickness, length or density that occur during component manufacture, but which do not affect the functionality of a device. However, they can be used as a unique, digital identification key that cannot be counterfeited.

"Electrical characteristics exist in microelectronics that were not designed - small variations from one device to another that exist due to the manufacturing process," said Jason Hamlet (pictured), a cybersecurity specialist at Sandia who developed the technology alongside electronics engineer Todd Bauer.

 "A PUF is a measurement of those variations, which are uncontrollable, unclonable and unique to individual devices. It’s a kind of fingerprint," he added. That means the tag-seal could not be removed and replaced with another without the switch being detected, according to the researchers.

The SecuritySeal prototype is a little bigger than a credit card and would fit a truck or cargo container. However, it could be larger or shrunk to fit other items such as a prescription medication bottle, according to Sandia.

The resistance properties of each SecuritySeal change if someone tries to lift, slide or remove the film from the surface to which it is adheres, and the PUF response is altered so the tamper is detected. A digital reader can be used to check the device remotely and can infer a change in signature if the tag-seal fails to properly respond.

"Seal a truck, seal a pallet, seal a box or a bottle," said Bauer. "You will know if the container has been opened and that what is in it is what is supposed to be in it."

Sandia - a subsidiary of Lockheed Martin - has a long history of research into tamper detection and continues to advance the field, providing technologies to the International Atomic Energy Agency and others.