p3-circle

A STARK framework over the unit circle of a finite field, following the Circle STARKs paper by Haböck, Levit and Papini. This enables Mersenne-31, which has no large two-adic multiplicative subgroup, to be used as a STARK field.

Key items:

• CirclePcs — the p3_commit::Pcs instantiation over circle domains
• CircleDomain, CircleEvaluations — circle-group evaluation domains and the circle FFT (cfft)
• DEEP quotients and circle-specific FRI folding for the opening argument

Part of Plonky3, dual-licensed under MIT and Apache 2.0.