Realistic Randomness for Quantum Cryptography Applications

Access to good randomness is crucial for many cryptographic primitives and protocols, both classical and quantum, no matter if they are information-theoretically or only computationally secure. Security proofs usually assume that the honest parties have access to perfectly uniform and unpredictable local randomness. However, this assumption is rarely met in practice, and deviations could introduce security loopholes. This poster aims to raise awareness about the critical importance of good randomness in quantum cryptography. It will briefly explain how we can model randomness sources and explicitly identify all the randomness used in a decoy-state prepare-and-measure BB84 protocol