// used for the RO challenges.
// From [Srinath Setty](research.microsoft.com/en-us/people/srinath/): In Nova, soundness error ≤
// 2/|S|, where S is the subset of the field F from which the challenges are drawn. In this case,
// we keep the size of S close to 2^128.
pub const N_BITS_RO: usize = 128;