Encryption and security does usually not get any better by pretending its secure and not letting anyone dig around the solution.

Indeed. Schneier has some excellent discussion on this topic, singling out closed source encryption as always eventually being cracked, and the security world's consideration of open source as a pre-requisite for security:

http://www.schneier.com/crypto-gram-9909.html

I've never understood how anyone with at least an ounce of intelligence can claim that something is more secure just because it's closed source.