Transposition
Rail fence, columnar (one or two keywords), route (a spiral, or quarter turns as in Kryptos part 3), scytale and the turning grille, both ways, with diagrams. Rail fence is solved by trying every rail count, columnar by simulated annealing up to 20 columns and double transposition up to about 12. Plutarch (Lysander 19) describes the Spartan scytale; whether it served as a cipher is debated (Kelly, 1998).