Definition
Plain language
The way computers store decimal numbers using a fixed number of digits, rounding off after each step.
As stated in the literature
A finite-precision representation of real numbers; because operations round and are order-sensitive, different hardware accumulates slightly different results on identical computations, the basis of hardware fingerprinting in FloatDoor.
Also called: floating point, finite-precision arithmetic
Why it matters: These tiny rounding differences let identical computations leave distinct hardware fingerprints, which is exactly what a platform-triggered backdoor exploits.
For example, adding the same long list of decimals in a different order can give a slightly different last digit on two different computers.
Heard on the show
“And the floating-point sanity check?”Episode 032 — A Sticky-Note for Every Layer: Letting Transformers Remember What They Were Just Thinking