Alexander von Kryha and His Encryption Machines

Operational Use and Cryptanalysis of the Kryha Cipher Machine

“…Nevertheless, it enjoyed a long lifetime and surprisingly wide use, but did not make fortunes for either its inventor or its investors [38].…”

“…38 The value of 23 for k is suggestive of a fixed precursor of the later adjustable control wheel, especially since the actual sum of the kicks is 179 (the number of teeth on the drive wheel of the later machine), but an examination of the corresponding stepping pattern recovered by Hitt shows that it could not have been produced by any possible setting of the grub screws on the later control wheel. 39 [7], [10], and [38] give A. M. Evalenko as the name of purchaser of the North American rights to the machine. Whether ''George'' and ''A.…”

“…9 In the electrical version of the early machine the alphabet disks are replaced by commutator-like arrangements providing an electrical pathway between moving inner and fixed outer ring. There is no provision for permuting the alphabets on these rings; the equivalent function is performed by plug-and-socket arrangements for permuting the 26 wires joining the central ciphering unit to the two electrical typewriters (these are visible in Figure 7 of [38]). Of three extant patent applications covering the electrical version, only the earliest mentions this possibility (France 618952, see note 6).…”

“…A 17-segment control wheel was used to produce the first set and a 23-segment wheel for the second, with corresponding values for k (not just s) of 17 and 23. 38 Given the short lengths of the message beginnings that were used, no advantage could be taken of isomorphisms or of simplifying assumptions such as taking k to be 1. Hitt's description of the crucial steps of recovering the plain and cipher component sequences from the solved messages is rather terse.…”

“…The demonstration was given by Alexander von Kryha himself and one George Evalenko, 39 Hitt was accompanied by a colleague, one 37 Within GC&CS, at least three different sections worked on Kryha traffic: ISOS-Intelligence Section, Oliver Strachey-responsible for solutions of hand ciphers used by German clandestine services such as the Abwehr [40]; ISK-Intelligence Section, Knox-responsible for solutions of traffic using unsteckered versions of the Enigma machine, including the special Enigma used by the Abwehr [3]; and the Commercial Section, based at Aldford House in London [13]. 38 The value of 23 for k is suggestive of a fixed precursor of the later adjustable control wheel, especially since the actual sum of the kicks is 179 (the number of teeth on the drive wheel of the later machine), but an examination of the corresponding stepping pattern recovered by Hitt shows that it could not have been produced by any possible setting of the grub screws on the later control wheel. 39 [7], [10], and [38] give A. M. Evalenko as the name of purchaser of the North American rights to the machine.…”