Alice wants to leave a message for Bob. So she encrypt a signed message with Bob's public key.
Then leaves it at a dead drop service.
Then later Bob arrives and checks the messages and attempts to trial decrypt all of them to see if there are any addressed to him.
When Bob finds Alice's message, he manages to decrypt and read it.
However in order to avoid the vandalization of the dead drop, he can only remove the message from the dead drop if he can prove he is indeed the recipient.
Is there a way to do that without revealing the message and his identity?