  Quantum bit seal is a way to encode a classical bit quantum mechanically so
that everyone can obtain non-zero information on the value of the bit.
Moreover, such an attempt should have a high chance of being detected by an
authorized verifier. Surely, a reader looks for a way to get the maximum amount
of information on the sealed bit and at the same time to minimize her chance of
being caught. And a verifier picks a sealing scheme that maximizes his chance
of detecting any measurement of the sealed bit. Here, I report a strategy that
passes all measurement detection procedures at least half of the time for all
quantum bit sealing schemes. This strategy also minimizes a reader's chance of
being caught under a certain scheme. In this way, I extend the result of
Bechmann-Pasquinucci et al. by proving that quantum seal is insecure in the
case of imperfect sealed bit recovery.
