Abstract: The security analysis of a practical QKD has two broad aspects: security of finite-length keys and device modelling. The former studies the trade-off between the producible secret key length, security parameters, and system parameters, while the latter looks at the best possible device models for the actual implementation. In this tutorial, we will introduce the basic concepts of finite-key security and survey some of the recent security analyses for source leakages (Trojan horse attacks, etc).
