Method of implementing a physical unclonable function

A device comprising a plurality of primitives coupled in pairs (P1, . . . , P6), wherein the primitives are electronic units,

• wherein said primitives are configured for being one-time programmable by changing their state from a not-programmed state to a programmed state through application of a burning energy to said, primitives, wherein the device comprises:
• a selector configured to select a subset of the pairs of primitives,
• a comparator configured to assess a difference between electrical characteristics values provided by primitives belonging to each pair of the subset, and configured to qualify all pairs of primitives for which the assessed difference is higher than a reference threshold, said qualified pairs corresponding to primitives selected for implementing a physical unclonable function providing a response representative of the device,
• and a programming circuit configured to program at least one primitive of each pair of primitives for which the assessed difference is lower than said reference threshold, by applying a burning energy to said at least one primitive so as to differentiate qualified pairs of primitives from those that are not qualified.