Fig. 1: Voxelated random wrinkles of physical unclonable function (PUF).

a Schematic illustration of encoded information stored in random wrinkles with spatial optical retardation varying caused by birefringence of the anisotropic medium. Random anisotropic wrinkles can generate an infinite number of security codes which are 2D binary codes. b Unstandardized security patterns can be implemented, and grayscale can be adjusted based on the retardation of each individual pixel that comprises the pattern. When passing through a wave plate (λ = 530 nm), the retardation can be observed as blue- and red-shifted pixels. The resulting wrinkles can then be transformed into a distinctive binary code through image processing. All scale bar represents 50 μm. c Overall rw-PUF data encryption and application through the following process: (i) The rw-PUF is generated through a random wrinkling process. (ii) The pixelated retardation from a single rw-PUF, formed by the angle to the crossed polarizer, is encrypted and stored in the data cloud. (iii) The stored data is decrypted and authenticated as required for the application