let hop_pk_blinding_factor = {
let mut hmac = HmacEngine::<Sha256>::new(b"blinded_node_id");
hmac.input(encrypted_data_ss.as_ref());
let hop_pk_blinding_factor = {
let mut hmac = HmacEngine::<Sha256>::new(b"blinded_node_id");
hmac.input(encrypted_data_ss.as_ref());