A White-Box Encryption Scheme Using Physically Unclonable Functions

When a cryptographic algorithm is executed in a potentially hostile environment, techniques of White-Box Cryptography are used to protect a secret key from a fully-privileged adversary. However, even if the adversary is not able to extract the secret key from the implementation, they might lift the entire white-box code and execute it (this is called a code lifting attack). In this work, we introduce an encryption scheme that can be implemented on an untrusted environment and is still secure even if the white-box code has been lifted. We base our proposal on a Physically Unclonable Function (PUF) to ensure the execution context of our so-called PUF-based encryption scheme. This way, the encryption is "locked" by a particular device.