In designing security solutions, cryptography as well as suitable organizations and procedures are of equal import. The focus of this article is on the creation of nationwide security infrastructures and applications, and the experience that Cybernetica has gained from the design and implementation of such projects. System users are frequently the source of security concerns. The developer's aim is consequently to keep systems simple, with a minimum of human interaction. Based on these principles, complex and security-critical applications have been developed and implemented in Estonia. We provide the Estonian e-voting solution as an example of a complicated system which can be user friendly.