WookPark of Kyung Hee University in South Korea has developed a security key that uses tiny plastic particles to create hard-to-replicate fingerprint keys.
Microscopic wrinkles squeezed onto the surface of tiny plastic particles can be used to make hard-to-replicate security keys.
These randomly formed wrinkles resemble human fingerprints, says Derek Breid of St. Vincent's College in Pennsylvania. Because each set of wrinkles is completely unique, these particles could be used to identify individuals instead of security cards or fingerprints. They are also used for precious art, so that people can be sure that the real art is being traded.
According to the technology developer, WookPark of Kyung Hee University in South Korea, keys made in this way are nearly impossible to clone. Their method involves adding a thin layer of silica to plastic pellets, then soaking them in ethanol and waiting to dry. As the particles dry, wrinkles that form within the silicon oxide layer will create a fingerprint-like structure.
Slight temperature differences or the presence of dust or other particles would make the structure unique. "It's an extremely chaotic random process," Breid said, making it nearly impossible for others to accurately replicate the wrinkle pattern. Making wrinkles this way is easier and less expensive than laser etching a specific maze. "It's very important not to use expensive fabrication techniques," he said.
Although forming this pattern is largely random, Park and team have developed ways to control where some wrinkles form. They hardened parts of the plastic pellets by placing them in sunlight, and each hardened point formed a "decision point" where wrinkles end, bend or separate.
Researchers can control at least some of these parameters and can easily share information. Controlling a group of particles in the same way (eg, exposing them to the same light patterns) can form matched groups with similar decision points. Although the overall fingerprint is still random, a scanner that reads the particle will be able to identify the location of the decision point and thus, like a security card, know a key that belongs to a group of similar keys, that is, they can open the same door , so they can be shared among groups for which specific information is available.
Jan Genzer of North Carolina State University was impressed by the research. "You have great control over the length and shape of the wrinkles," he says.
Park and team are working on a smaller scanner to detect this pattern. They believe it would be more realistic to use conductive scanners that can read electronic information on surfaces in secure systems.
