ul@ohng69 said:
An yes, if kept the notion about the adjacent letters and the disk
positions secret then all would be good. But then security by obscurity
always is.
Let's say you and I choose a secret crypto algorithm. You choose
SHA-256, but don't tell me. I, in my brilliance and wisdom,
choose ROT-13. Nobody knows what my algorithm is! But
keeping that a secret would be useless, because cryptanalysis would
crack it instantly.
Security by obscurity is not always good; cryptanalysis can find
patterns in the encrypted signal without knowing the original
algorithm. Having a smaller set of encryption keys ultimately
means that those patterns will be easier to detect.