Symmetries in Quantum Key Distribution and the Connection between Optimal Attacks and Optimal Cloning

Understand

We investigate the connection between the optimal collective eavesdropping attack and the optimal cloning attack where the eavesdropper employs an optimal cloner to attack the quantum key distribution (QKD) protocol.

• The analysis is done in the context of the security proof in [Devetak and Winter, Proc.
• of the Roy.
• Soc.