> We define the notion of one-shot signatures, which are signatures where any secret key can be used to sign only a single message, and then self-destructs. While such signatures are of course impossible classically, we construct one-shot signatures using quantum no-cloning.

Well, okay. I don't know enough about quantum cryptography to really evaluate this idea. However, conventionally, the way to do this is a trusted execution environment that attests to the hash of the software running and it promises to have really really deleted the private key or the secret after it is transferred. Advantage of this scheme is that it does not require me to study more cryptography.