This incorporation of the randomness characterization and evaluation processing into one unit reduces the risk of man-in-the-middle and side-channel attacks aimed at the communication between the two areas.
Few characteristics of Via PUF are followings: The Via PUF based Hardware RoT (Root of Trust) chips are currently applied in various markets such as telecommunications, appliances, and IoT devices in the forms of Wifi/BLE modules, smart door locks, IP cameras, IR sensor hub, etc.
Given an input challenge, a race condition is set up in the circuit, and two transitions that propagate along different paths are compared to see which comes first.
The use of SRAM as a PUF was introduced in 2007 simultaneously by researchers at the Philips High Tech Campus and at the University of Massachusetts.
[7][23][24] Since the SRAM PUF can be connected directly to standard digital circuitry embedded on the same chip, they can be immediately deployed as a hardware block in cryptographic implementations, making them of particular interest for security solutions.
Several research papers explore SRAM-based PUF technology on topics such as behavior, implementation, or application for anti-counterfeiting purposes.
Due to deep submicron manufacturing process variations, every transistor in an Integrated Circuit (IC) has slightly different physical properties.
In order to use SRAM PUF reliably as a unique identifier or to extract cryptographic keys, post-processing is required.
The dominant aging effect in modern ICs that at the same time has a large impact on the noisy behavior of the SRAM PUF is NBTI.
In 2010, NXP started using SRAM PUF technology to secure SmartMX-powered assets against cloning, tampering, theft-of-service and reverse engineering.
[8][40][41][42] There are several important advantages to leveraging random resistance variations in the metal resources of an IC including: The Bistable Ring PUF or BR-PUF was introduced by Q. Chen et al.
By duplicating the inverters and adding multiplexers between stages, it is possible to generate exponentially large number of challenge-response pairs from the BR-PUF.
Thus, DRAM PUFs could be a source of random but reliable data for generating board identifications (chip ID).
IC design houses can strongly enhance security level by implementing oxide rupture PUF in its IC design, without concerns about the reliability and life time issue and can get rid of the additional costs from complicated ECC (Error Correction Code) circuits.
Moreover, the placement of this opaque PUF in the top layer of an IC protects the underlying circuits from being inspected by an attacker, e.g. for reverse-engineering.
When an attacker tries to remove (a part of) the coating, the capacitance between the wires is bound to change and the original unique identifier will be destroyed.
[49] As the size of a system is reduced below the de Broglie wavelength, the effects of quantum confinement become extremely important.
The intrinsic randomness within a quantum confinement PUF originates from the compositional and structural non-uniformities on the atomic level.
The physical structure of the magnetic media applied to a card is fabricated by blending billions of particles of barium ferrite together in a slurry during the manufacturing process.
To pour the sand to land in exactly the same pattern a second time is physically impossible due to the inexactness of the process, the sheer number of particles, and the random geometry of their shape and size.
When the slurry dries, the receptor layer is sliced into strips and applied to plastic cards, but the random pattern on the magnetic stripe remains and cannot be changed.
An optical PUF which was termed POWF (physical one-way function)[53][16] consists of a transparent material that is doped with light scattering particles.
Imperfections created during crystal growth or fabrication lead to spatial variations in the bandgap of 2D materials that can be characterized through photoluminescence measurements.
It has been shown that an angle-adjustable transmission filter, simple optics and a CCD camera can capture spatially-dependent photoluminescence to produce complex maps of unique information from 2D monolayers.
[17] The digitally modulated data in modern communication circuits are subjected to device-specific unique analog/RF impairments such as frequency error/offset and I-Q imbalance (in the transmitter), and are typically compensated for at the receiver which rejects these non-idealities.