Cocoon-PUF, a novel mechatronic secure element technology

A new Physical Unclonable Function (PUF) technology is proposed. The technology is targeting the implementation of a highly secure unclonable electromechanical device. The resulting system includes a physical unit providing identification properties mutually-dependent on both microelectronic and mechanical components. The technology is based on combining very high frequency wave propagation, scattering and reflection based on dielectric and/or magnetic particles or composites (potted) in matrices of a closed medium with mechanical spatial factors related to encapsulation material. It is assigned the name Cocoon-based Physical Unclonable Function (Cocoon-PUF). The resulting fingerprint properties are related to the transmitters and sensors integrated on the chip die, the spatial randomized distribution in the encapsulation matrix (potting material), offering unpredictable and hence practically impossible to clone or duplicate mechatronic units. The targeted Cocoon-PUF is to build rigging-resistant non-silicon based mechanical footprints in tamper resistant packaging. Additionally, the proposed technology fits to the tendency and requirement of protection against Electro-Magnetic-Pulse (EMP) surges (as TEMPEST design), which can be seen as an additional pleasant side effect of Electro-Magnetic-Compatibility (EMC) of the Cocoon protection principle. The paper presents the basic technology principles and shows first promising prototyping results of that new technology.