A highly modular and configurable Python framework for QKD

Quantum Key Distribution (QKD) requires not only the transmission and detection of quantum states, but also a complex set of algorithms that post-process the correlated measurement results to produce secret keys. Furthermore the protocol steps need to be coordinated and controlled. We present a highly modular and therefore universal software framework that we apply on a regional BBM92-type QKD link, and presently extend towards satellite-based QKD and towards MDI-QKD protocols. Besides performing the post-processing algorithms, it controls various hardware components, provides tools for real time analysis and debugging of both software and optical alignment. It allows the selective acceleration of performance-critical algorithms and supports distributed execution, including a public, but authenticated, classical communication channel.