def reencrypt(kfrag: KFrag,
capsule: Capsule,
provide_proof: bool = True,
metadata: Optional[bytes] = None,
verify_kfrag: bool = True) -> CapsuleFrag:
if not isinstance(capsule, Capsule) or not capsule.verify():
raise Capsule.NotValid
if verify_kfrag:
if not isinstance(kfrag,
KFrag) or not kfrag.verify_for_capsule(capsule):
raise KFrag.NotValid
rk = kfrag.bn_key
e1 = rk * capsule.point_e # type: Any
v1 = rk * capsule.point_v # type: Any
cfrag = CapsuleFrag(point_e1=e1,
point_v1=v1,
kfrag_id=kfrag.id,
point_precursor=kfrag.point_precursor)
if provide_proof:
cfrag.prove_correctness(capsule, kfrag, metadata)
return cfrag
def hop_reencrypt(kfrag: KFrag,
cfrag: CapsuleFrag,
capsule: Capsule,
metadata: Optional[bytes] = None,
provide_proof: bool = True) -> CapsuleFrag:
rk = kfrag.bn_key
e1 = rk * cfrag.point_e1
v1 = rk * cfrag.point_v1
cfrag = CapsuleFrag(point_e1=e1,
point_v1=v1,
kfrag_id=kfrag.id,
point_precursor=kfrag.point_precursor)
if provide_proof:
cfrag.prove_correctness(capsule, kfrag, metadata)
return cfrag