Public Key Encryption with Secure Key Leasing

Understand

We introduce the notion of public key encryption with secure key leasing (PKE-SKL).

• Our notion supports the leasing of decryption keys so that a leased key achieves the decryption functionality but comes with the guarantee that if the quantum decryption key returned by a user passes a validity test, then the user has lost the ability to decrypt.
• Our notion is similar in spirit to the notion of secure software leasing (SSL) introduced by Ananth and La Placa (Eurocrypt 2021) but captures significantly more general adversarial strategies.
• In more detail, our adversary is not restricted to use an honest evaluation algorithm to run pirated software.