in src/group/elliptic_curve.rs [110:114]
fn deserialize_scalar(scalar_bits: &[u8]) -> Result<Self::Scalar> {
SecretKey::<Self>::from_be_bytes(scalar_bits)
.map(|secret_key| *secret_key.to_nonzero_scalar())
.map_err(|_| Error::Deserialization)
}