The following papers created one-way functions on words for resilient information hiding in text, first one through synonym substitutions, second one through ty

The following papers created one-way functions on words for resilient information hiding in text, first one through synonym substitutions, second one through typos: "The hiding virtues of ambiguity: quantifiably resilient watermarking of natural language text through synonym substitutions", U. Topkara et. al. MMSec'06 https://www.cerias.purdue.edu/assets/pdf/bibtex_archive/2006-61.pdf https://www.cerias.purdue.edu/assets/pdf/bibtex_archive/2006... "Information hiding through errors: A confusing approach", M.Topkara et. al. SPIE'07 http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.94.1426 http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.94.1...