No one seems to like the "German Eichrecht", esp. not manufacturers and operators of charging infrastructure, yet it provides security and transparency of your charging sessions. This talk will give an introduction to the fundamentals and requirements of the calibration law and explain you why Open Source of the "Chargy Transparency Software" is not only eyecandy, but a fundamental part of the security goals and guarantees for EV drivers. From a software developer's point of view the German calibration law is not so much about measuring energy correctly or invoicing the correct prices, but a first step towards a more modern zero trust architecture for the e-mobility charging infrastructure. This security update is sorely needed, as todays architecture is full of well-known, yet unaddressed bugs and design flaws mainly caused by the very the bad communication of people in distributed systems and across gated communities. Besides solving technical goals, the German Eichrecht also tries to make sure, that the security gurantees also reach the end users and give them all required tools, data and information to verify the correctness of their charging sessions. Therefore for us Open Source is not only a non-functional, nice-to-have marketing feature off the calibration law or just more cost effective way of shared software development, but a fundamental (functional) requirement. Unfortunately the applicability of the calibration law for those end users is still very low. With the upcoming version 2.x of our Chary Transparency Software we not only introduce multi-language support to support the adoption of the German Eichrecht all over Europe, but also present new services like a real public key infrastructure for energy meter public keys and incremental charge transparency records for a "Real-Time Eichrecht". Of course we are interested in your feedback and future contributions to this Open Source Project.