[MA] Provably Quantum-Secure Message Authentication Code
Provably Quantum-Secure Message Authentication Code
The master thesis examines the use of nonces in the design of quantum-secure protocols. In a previous work, a generic transformation that makes a classically-secure MAC scheme quantum-secure was introduced. We show that this transform is not secure in general. However, we then argue that the transform does its intended purpose for many specific cases. To illustrate this, we apply it to the CBC-MAC scheme and prove its security. We do this by directly proving its existential unforgeability under quantum chosen message attack security. This allows us to avoid technical complications, and produces a short security proof.