Upper bounds of a class of imperfect quantum sealing protocols

The model of the quantum protocols sealing a classical bit is studied. It is shown that there exist upper bounds on its security. For any protocol where the bit can be read correctly with the probability $\alpha$, and reading the bit can be detected with the probability $\beta$, the upper bounds are $\leqslant 1/2$ and $\alpha +\beta \leqslant 9/8$.Comment: 5 pages, 1 figure. Add an example on how to break the majority voting schem