Your definition of secrecy is missing the point. By your definition, nothing can be secret, as anything can be represented as numbers. Secrecy comes from not kn

Your definition of secrecy is missing the point. By your definition, nothing can be secret, as anything can be represented as numbers. Secrecy comes from not knowing which number is the correct one, not from not being able to construct the number in principle. The useful distinction that is usually made between secrecy and obscurity hinges essentially on how easy it is to swap out the thing that's unknown to the attacker that security depends on. If your crypto key leaks, you generate a new one, and you are secure again, which is why the crypto key is a secret. If your source code leaks, no such thing, which is why hiding it is obscurity.