[[Kvanteprotokoller]] som tillater en part å bevise ovenfor en annen part at et element ble slettet. [EC:HKMNPY24](https://eprint.iacr.org/2023/236) argumenterer for at man kan få en form for "everlasting security" gitt at en server kan bevise ovenfor brukeren kryptografiske elementer som f.eks. chiffertekster ble slettet: > A receiver possessing a quantum cryptographic object (such as ciphertext) can issue a certificate showing that the receiver has deleted the cryptographic object and information included in the object (such as plaintext) was lost. If the certificate is valid, the security is guaranteed even if the receiver becomes computationally unbounded after the deletion. Many cryptographic primitives are known to be impossible (or unlikely) to have information-theoretical security even in the quantum world. Hence, certified everlasting security is a nice compromise (intrinsic to quantum).