He became managing director of TeleTrusT, an organisation which has established reliable conditions for trustworthy application of information and communication technologies in Germany and beyond.
Reimer directed the association towards an internationally respected competence centre for applied cryptography and biometrics.
He initiated project groups to work on specifications for card terminals, encryption and client/server authentication.
He worked towards publications, such as the 1995 book "Digitale Signatur & Sicherheitssensitive Anwendungen (Digital signature & security sensitive applications), reports such Kryptographische Verfahren im Gesundheits- und Sozialwesen (Cryptographic methods in the health and social care sector) and Kriterienkatalog zur Bewertung der Vergleichbarkeit biometrischer Verfahren (Criteria catalogue for assessing the comparability of biometric methods).
[6] He is among the publishers of the trade magazine Datenschutz und Datensicherheit (DuD) of the Vieweg Verlag[2] Reimer was awarded the Fraunhofer SmartCard-Preis.