Hardware Security
Which describes a PUF (physically unclonable function)?
- AA mechanism that uses per-chip manufacturing variation to produce values unique to each chip and hard to clone
- BA mechanism writing the same value into every chip
- CA product number printed on the chip surface
Show answer and explanation
Answer: A. A mechanism that uses per-chip manufacturing variation to produce values unique to each chip and hard to clone
Even chips of the same design differ slightly in transistor threshold voltages and wire delays due to manufacturing variation. A PUF reads out these differences to produce a value unique to each chip. Not even the manufacturer can control the variation, so producing a chip with the same value is very difficult. PUFs are used for device authentication and as a source for generating keys.
- A. Correct. It is like a fingerprint for the chip.
- B. Values must differ from chip to chip.
- C. A printed number is easy to copy.