Skip to main content

is_on_curve

arcana::ecc::curve

Function is_on_curve 

Source 
pub fn is_on_curve<const LIMBS: usize>(
    x: &FieldElement<LIMBS>,
    y: &FieldElement<LIMBS>,
    params: &CurveParams<LIMBS>,
) -> bool
Expand description

Check whether the affine point (x, y) lies on the short Weierstrass curve y^2 = x^3 + a*x + b defined by params.

Critical for ECDH: any externally-supplied public key must be validated with this function before being multiplied by a secret scalar. Otherwise an “invalid curve attack” can recover bits of the secret key by feeding crafted off-curve points whose order in the broken group is small.

Returns true iff the affine equation holds modulo p.