Reproducibility of artificial multiple scattering media

Evangelos Marakis, Wouter van Harten, Ravitej Uppu, Pepijn Willemszoon Harry Pinkse

Research output: Contribution to conferencePosterOther research output


State of the art authentication systems depend on physical unclonable functions (PUF) [1], physical keys that are assumed unclonable due to technological constraints. Random scattering media, dielectric materials with rapid and random refractive index variations, are considered as ideal optical PUFs [2,3]. The optical response to coherent light illumination of a scattering-medium-based optical PUF will be a complex interference pattern of bright and dark spots, known as speckle. This speckle pattern is seemingly random but uniquely defined by the illumination conditions and the scattering medium itself.
The assumption of unclonability relies on the notion that a speckle pattern is extremely sensitive to the exact location and shape of the scatterers [4]. We attempt to falsify this assumption with direct laser writing (DLW) [5]. This technique in principle has a resolution of 10nm and feature sizes of 100nm. We investigate theoretically if these specifications allow to fabricate multiple copies of optical PUFs that cannot be discriminated by a QSA readout device. In addition we explore the practical feasibility of fabricating strongly-scattering artificial optical PUFs with DLW.

[1] U. Rührmair, S. Devadas, and F. Koushanfar, in Introd. to Hardw. Secur. Trust, edited by M. Tehranipoor and C. Wang (Springer New York, New York, NY, 2012), pp. 65–102.
[2] R. Pappu, B. Recht, J. Taylor, and N. Gershenfeld, Science 297, 2026 (2002).
[3] S. A. Goorden, M. Horstmann, A. P. Mosk, B. Škorić, and P. W. H. Pinkse, Optica 1, 421 (2014).
[4] R. Berkovits, Phys. Rev. B 43, 8638 (1990).
[5] J. Fischer and M. Wegener, Laser Photonics Rev. 7, 22 (2013).

Original languageEnglish
Publication statusPublished - 22 Jun 2016
EventPALS 2016 - Exeter, UK
Duration: 21 Jun 201624 Jun 2016


ConferencePALS 2016
CityExeter, UK


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