He also worked for Joseph Booth's Polygraphic Society. It then returned to Polygraphic Hall, disbanding in August 1860. Born in Riga 1949, he studied at the Moscow Polygraphic Institute. See "Bernhardt v. Polygraphic Co.", 350 U.S. 198, 203, 76 S.Ct. The polygraphic consonant signs are treated as single letters. A polygraphic test could be viewed as a working memory task. In 1989, he graduated from Moscow State University of Printing Arts (formerly Moscow Polygraphic Institute). Polygraphic systems do provide a significant improvement in security over monoalphabetic substitutions. In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra.