  Seal in classical information is simply impossible. Since classical
information can be easily copied any number of times. Based on quantum
information, esp. quantum unclonable theorem, quantum seal maybe constructed
perfectly. But it is shown that perfect quantum seal is impossible, and the
success probability is bounded. In this paper, we show how to exceed the
optimal bound by using the TCF (Trapdoor Claw Free) functions, which can be
constructed based on LWE assumption. Hence it is post-quantum secure.
