Module prio::field

Finite field arithmetic.

Basic field arithmetic is captured in the FieldElement trait. Fields used in Prio implement FftFriendlyFieldElement, and have an associated element called the “generator” that generates a multiplicative subgroup of order 2^n for some n.

Structs

• BitvectorRepresentationIter
  This iterator returns a sequence of field elements that are equal to zero or one, representing some integer in two’s complement form. See FieldElementWithInteger::encode_as_bitvector.
• Field64
  GF(18446744069414584321), a 64-bit field.
• Field128
  GF(340282366920938462946865773367900766209), a 128-bit field.
• Field255
  GF(2^255 - 19), a 255-bit field.
• FieldPrio2
  Same as Field32, but encoded in little endian for compatibility with Prio v2.

Enums

• FieldError
  Possible errors from finite field operations.

Traits

• FftFriendlyFieldElement
  Objects with this trait represent an element of GF(p), where p is some prime and the field’s multiplicative group has a subgroup with an order that is a power of 2, and at least 2^20.
• FieldElement
  Objects with this trait represent an element of GF(p) for some prime p.
• FieldElementWithInteger
  Extension trait for field elements that can be converted back and forth to an integer type.
• Integer
  An integer type that accompanies a finite field. Integers and field elements may be converted back and forth via the natural map between residue classes modulo ‘p’ and integers between 0 and p - 1.

Functions

• random_vector
  Generate a vector of uniformly distributed random field elements.