  A quantum seal is a way of encoding a message into quantum states, so that
anybody may read the message with little error, while authorized verifiers can
detect that the seal has been broken. We present a simple extension to the
Bechmann-Pasquinucci majority-voting scheme that is impervious to coherent
attacks, and further, encompasses sealing quantum messages by means of quantum
encryption. The scheme is relatively easy to implement, requiring neither
entanglement nor controlled operations during the state preparation, reading or
verification stages.
