- red denotes signals carrying secret plaintext;
- black denotes signals carrying ciphertext.
Is there any generally agreed coloring for the analogous integrity question? i.e.:
- a color which denotes signals where integrity matters (or maybe this is "all of them" and we don't need a specific choice of color); and
- a color which indicates a signal with cryptographic integrity protection of some kind.
Non-color visual notations also welcome for several reasons:
- things still get printed in monochrome;
- color vision is not uniform among humans;
- using too many color notations at once leads to angry fruit salad rather than clear diagrams.