Overview
A Physically Unclonable Function (PUF) is a function that is instantiated as a physical structure
on a chip, having behaviour that is easy to evaluate but hard to predict. It measures physical
properties of a specific IC device based on normal process manufacturing variations that exist down
to the individual die level. One can think of a PUF as a digital fingerprint of each individual chip,
or in mathematical terms, a PUF is a physical instantiation of a one-way function.
The PUF concept emerged in the early 1990s, and today, integrated circuits using PUFs are entering
the marketplace as a more efficient means of implementing certain applications in practical cryptography.
In particular, the PUF serves as a unique identifier that can be used for cryptographic keying or
trustworthy identification.
Since a PUF is inherently unclonable, this means that each PUF device has a unique and unpredictable
way of mapping a challenge to a response. Even when ICs are manufactured with exactly the same process
design rules, it is not feasible to construct a PUF in any particular IC that has the same challenge-response
behavior as another. This is because the PUF circuitry measures certain small process variations that
are random but still within the control limits and design rule ranges of the given process.
Applications for PUF
In terms of applications, rather than the conventional approach of using a single cryptographic key,
PUFs can be used to efficiently implement challenge-response authentication. On receipt of a challenge
stimulus, the PUF is used to generate an unpredictable (but repeatable) response. Hence, a unique device
identity is established for each individual IC chip. As the PUF characteristics are not directly revealed
by the challenge-response mechanism, such an IC is highly resistant to spoofing attacks.
Applications for PUFs include the following:
- Device Authentication
- Key Generation and Management
- Random Number Generation
- Secure/Trusted Boot
- Trust Anchor or Root of Trust
- HW/SW Binding
- IP Protection and Metering
- Anti-Counterfeiting or Cloning
- Basis for Electronic Payments/Transactions
PUFs can be implemented efficiently and at a low cost relative to other technologies which achieve the
same goals. Furthermore, this technology is becoming a cornerstone to enable Trust in electronics
for numerous emerging security needs.
Contact
Helion is currently assessing the interest and needs of its customers with regard to PUF IP
for soft FPGA and hard ASIC applications. We welcome your enquiries as we develop our plans
for this exciting new technology. Please feel free to email us at
helioncores@heliontech.com for a more detailed discussion.
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