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Quantum confinement for unique identities

Research output: Contribution to conference Speech

Publication date22/06/2017
<mark>Original language</mark>English


Physical unclonable functions (PUFs) are physical components that translate an input challenge into a unique response that cannot be predicted without access to the component itself. PUFs can integrated into devices to ensure trust in everyday interactions and to act as a defence; guarding against the counterfeiting of goods by providing robust identities. In the past these functions have relied on classical phenomena, including signal speed through a ‘race’ wire (Arbiter PUFs [1]) or probabilistic switching of electronic latches. Many PUFs have been found to be vulnerable to response modelling [2] or direct cloning [3] attacks, and have limitations on minimum size. These vulnerabilities and constraints prompt turning away from classical PUF methodologies and towards architectures exploiting quantum phenomena, such as quantum confinement.
We propose a PUF concept that operates on the principles on quantum confinement through the fluctuation of the first energy level of a resonant tunnelling diode (RTD) [4]. These fluctuations derive from intrinsic atomic scale variations in the manufacture of each RTD, and cause macroscopic changes in the specific electronic characteristics of the device [5]. In the simplest form, uniqueness in the RTDs would be derived from the current and voltage of the maximum tunnelling current position (see figure 1a) of each device. To be used as the constituent of a PUF, each resonant tunnel diode should be unique from one another, and stable after repeated readings.
We compared the current and voltage of this peak current position of 26 RTDs that could constitute the PUF. It was found that the peaks of each RTD do not overlap to a certainty of 99.997% (see figure 1b). The stability of repeat measurements of a single device was also examined, finding a deviation upon repeat readings of two standard deviations (95%) compared to the average current and voltage values (figure 1c). This analysis suggests that the resonant tunnelling diode is a strong candidate for use in the next generation of more secure, quantum derived security hardware.