I had never engaged in remote multishrink psychoanalysis on this scale before, so it was a fascinating experience. - Andrew S. Tanenbaum

Many security texts decompose the security of an information system in three components: confidentiality, integrity, and availability. Together, they are often referred to as "CIA". [They] constitute the core security properties that we must protect against attackers and eavesdroppers—such as the (other) CIA.

If you just want to use the system, instead of hacking on its internals, you don't need source code.

However, as every parent of a small child knows, converting a large object into small fragments is considerably easier than the reverse process.