I often feel my line of work is grossly misrepresented by dizzying fields of esoteric numbers and references to ancient cryptography when I'm happy to find myself many of my days engrossed in the security characteristics of some powerful technology used right now in the real world.

Have you never worked a custom written crypto algo in your line of work ? For example, countries' army are the bane of sysadmins since they implement about every standard of networking since computer exists.

Working in infosec, you hardly have to crack an akbash cipher, but I'm pretty sure you'd had to understand a closed source algorithm.