A Danish Diplomatic Cipher with Table Swtiching in the 17th Century

A diplomatic cipher of Anthon W. v. Haxthausen is printed in Lindenfels (1819), the first book on cryptography in Danish, as I was taught by Franksen (1985), p.28-29. Lindenfels obtained it from "a noble benefactor" (see another article).

(The alphabet includes "Ö" after "Z.")

It is obvious that this is not a mere homophonic substitution cipher (for example, "1" appears on the 1st, 2nd, 3rd, and 4th row). Instead, this includes five different substitution alphabets. Fifteen numbers (9-15 and 30-37) are reserved as indices for indicating which alphabet is used. The alphabet can be switched within a ciphertext by these indices (see the example given).

This was contained, together with a similar cipher, in a sheaf of documents marked on the cover "Chiffres du Gr. Ecuyer Anthon W. v. Haxthausen dans ses mission à différentes Cour." ("Grand Ecuyer" means "Master in Chief of the Horse"). Franksen says Haxthausen was an envoy of Christian IV (1577-1648). But probably he relied on "Christianus quartus" of the example phrase. If the name refers to Anton Wolf von Haxthausen (1647-1694) (Wikipedia in German), who became head stable master in 1680, this must belong to the 1680s or thereabouts.


Ole Immanuel Franksen (1985), Mr. Babbage's Secret

J. B. Lindenfels (1819), Den hemmelige Skriwekonst eller: Chiffrer-og Dechiffrerkonsten [Art of Secret Writing] (Google)

©2021 S.Tomokiyo
First posted on 3 October 2021. Last modified on 3 October 2021.
Articles on Historical Cryptography
inserted by FC2 system