Draft:Cullinane diamond theorem

The Cullinane diamond theorem is a theorem about the Galois geometry underlying the Miracle Octad Generator of R. T. Curtis.

The theorem also explains symmetry properties of the sort of chevron or diamond designs often found on quilts.

The theorem has been in the Encyclopedia of Mathematics (of Springer and the European Mathematical Society) since May 10, 2013.

Background on the theorem and its author is at https://bio.site/cullinane.

Some historical background for the theorem: Ibáñez, Raúl, "The Truchet Tiles and the Diamond Puzzle."

For a cryptographic application, see a 2016 paper from SASTRA University —

V. Harish, N. R. Kumar and N. R. Raajan, "New visual secret sharing scheme for gray-level images using diamond theorem correlation pattern structure," 2016 International Conference on Circuit, Power and Computing Technologies (ICCPCT), Nagercoil, India, 2016, pp. 1-5, doi: 10.1109/ICCPCT.2016.7530155. keywords: {Visualization;Diamond;Correlation;Gray-scale;Computers;Encryption;Visual cryptography;Secret Sharing;Diamond theorem;stacking;sub blocks}.