Is there any cryptographic-related graphics drawing package?

Question

For example, fig 4.7, 4.8 shows in

http://williamstallings.com/Extras/Security-Notes/lectures/blockA.html

Answer 1

Seems like a task TikZ could perfectly handle. Those examples could help you get started (I did not find any pure cryptographic example, but feel free to contribute once you've created yours!).