'Security through Obscurity' is an insulting term used in Software - http://en.wikipedia.org/...
If the security of code depends on code being a secret, that means the code is insecure.
The best security and cryptographic algorithms are all public.
Let's take a simple example of a Microsoft Word file which you have protected with the password. The encryption algorithm used is AES.
AES (Advanced Encryption Standard) - the full description of the algorithm is here - http://en.wikipedia.org/...
It doesn't make the algorithm weak. The security of the algorithm depends on the secret key not on the code or algorithm. The algorithm isn't a secret - the password is the secret. Without the password, knowing the encryption code will not help you. The only way to crack the encryption is to either know the password or by brute force.
Linux, BSD Unix etc have their whole code public - this doesn't make the Operating Systems insecure. Code should never be sensitive.
If Healthcare.gov's security depends on the code being kept secret then it's already Dead on Arrival