[Cryptography] Drawing cipher diagrams

[Seth David Schoen]

Pierre Abbat writes:

> https://github.com/phma/DaphneCipher.jl
> It took me over a week to draw this diagram in the Gimp, using radius-65 
> circles because there are 36 integral points on such a circle (and I 
> discovered partway through that the 45° points are close to integral).

Inkscape is much more appropriate for drawing diagrams like this,
because it's based on vector rather than bitmap graphics.  It has lots
of tools for making objects align in specific ways with other objects in
your diagram, and for manipulating groups of objects as a unit.