Is the security of quantum cryptography guaranteed by the laws of physics?

It is often claimed that the security of quantum key distribution (QKD) is guaranteed by the laws of physics. However, this claim is content-free if the underlying theoretical definition of QKD is not actually compatible with the laws of physics. This paper observes that (1) the laws of physics pose serious obstacles to the security of QKD and (2) the same laws are ignored in all QKD “security proofs”.