Module field 

Prime field arithmetic for the Pasta curves (Pallas and Vesta).

Field elements are 256-bit integers stored as four 64-bit limbs in little-endian order. All arithmetic is modular with respect to the chosen curve’s prime modulus.

Moduli

• Pallas: 0x40000000000000000000000000000000224698fc094cf91b992d30ed00000001
• Vesta: 0x40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001

Structs

FieldElement

A 256-bit prime field element stored as four little-endian 64-bit limbs.

Enums

Curve

Identifies which Pasta curve modulus to use.

Constants

LIMBS 🔒

Number of 64-bit limbs in a field element.

PALLAS_FIFTH_ROOT_EXP 🔒

Fifth-root exponent for Pallas: (4p - 3) / 5, little-endian limbs.

PALLAS_MODULUS 🔒

The Pallas curve base field modulus, little-endian limbs.

VESTA_FIFTH_ROOT_EXP 🔒

Fifth-root exponent for Vesta: (4p - 3) / 5, little-endian limbs.

VESTA_MODULUS 🔒

The Vesta curve base field modulus, little-endian limbs.

Functions

add_limbs 🔒

Adds two 4-limb numbers, returning (result, carry).

gte_modulus 🔒

Returns true if a >= modulus.

mul_wide 🔒

Schoolbook multiplication producing an 8-limb (512-bit) result.

reduce_wide 🔒

Reduces a 512-bit product modulo p via shift-and-subtract.

shift_left_one 🔒

Shifts a 4-limb number left by one bit.

sub_limbs 🔒

Subtracts two 4-limb numbers, returning (result, borrow).