Knight's tour wiki (http://en.wikipedia.org/wiki/Knight's_tour)
Knight's Tours (https://larc.unt.edu/ian/research/puzzles/knightstour/)
Knight's Tour Challenge (http://kononovicius.lt/files/knight-tour-challenge/index.html)
Knight's tour at Wolfram Mathworld (http://mathworld.wolfram.com/KnightsTour.html)
Knight's Tours (http://geofhagopian.net/CS007A/assignments/Assignments_F15/ktpaper.pdf) - Ben Hill, Kevin Tostado (2004)
Knight's Tour Notes (http://www.ktn.freeuk.com/index.htm)
Number of possible knight's tours - OEIS (https://oeis.org/A165134)
There Are No Magic Knight's Tours on the Chessboard (http://mathworld.wolfram.com/news/2003-08-06/magictours/)
Modular Knight's Tours (http://www.borderschess.org/KTmodular.htm)
http://danthomasson.com/cubiosities.html
Oblique Quaternary Symmetry
Part 1 (http://www.ktn.freeuk.com/sd.htm)
Part 2 (http://www.ktn.freeuk.com/se.htm)
Direct Quaternary Symmetry (http://www.ktn.freeuk.com/sc.htm)
http://www.quizox.com/knightsmove.asp (http://www.quizox.com/knightsmove.asp)
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The vast majority of knight's tours are asymmetric or chaotic, with no discernable pattern, like this one:(http://www.gpj.connectfree.co.uk/adli.gif)
Some knight's tours are symmetic, like these:(http://www.chessbase.com/columns/images/knightstour04.gif)
A cubic knight's tour (re-entrant)(http://members.shaw.ca/hdhcubes/Image%20_Cube/cube_knight.gif)
Two similar closed (re-entrant) knight's tours with 180 degree symmetry (my own work, illustrated by Dan Thomasson (http://www.borderschess.org/KnightTour.htm)):(http://www.borderschess.org/WFristoe1.gif) (http://www.borderschess.org/WFristoe2.gif)
(http://www.borderschess.org/WFristoe1b.gif) (http://www.borderschess.org/WFristoe2b.gif)
An Image Encryption Algorithm Based on Knight's Tour and Slip Encryption-Filter (http://portal.acm.org/citation.cfm?id=1468727)
QuoteA new image encryption algorithm is proposed in the paper. Its essential idea is that, firstly, we produce a knight's tour matrix emended as slip encryption-filter template matrix; And then, we produce a knight's tour matrix again with the same size of the image waiting for encryption as a knight's tour slip matrix; Finally, we let the center of the slip encryption-filter template move along with the knight's tour slip matrix to do convolvsion operation, and achieve the cipher image. Experimental results show that the algorithm has perfert encryption effect, high encryption efficiency, simplity to achieve, huge secret key space and high security.
So, knight's tours may be applied after all, instead of pure geometry.