Re: M4 project
David Hamer <[email protected]>
| Newsgroups | gmane.science.cryptography.bletchley-park |
|---|---|
| Message-ID | <[email protected]> |
John... I believe the Kriegsmarine UKWD is somewhat rarer than that used by the Luftwaffe [the Heer is known to have used UKWD on only one key, in 1943]. Since the design of the lever and cams used to compress the wheel assembly are different in the army/ GAF and M4 Enigmas the UKWD types are not interchangeable. The difference is illustrated in Figures 5 and 6 of the first part of Phil Marks' seminal paper on UKWD: "Umkehrwalze D: Enigma's Rewirable Reflector - Part I", Cryptologia, Volume XXV(2), April 2001, pp.101-141. On page http://home.comcast.net/~dhhamer/begleit.htm it can be seen that at some point U-737 had UKWD in its Enigma inventory, noted by a pen-and-ink entry, but at some point this entry was deleted. U-737 was lost on 19 December 1944. David At 15:34 03/16/06, John Alexander wrote: >UKW 'D'. > >This was always thought to be a very rare item. I recently obtained a third example of 'D' - from Norway. > >John > >>it is not widely known that a naval version of UKWD existed. In dimension this physically occupied the space normally filled by a B/Beta or C/Gamma pair and in effect reduced the M4 to a three-wheel machine - albeit with a programmable reflector. The navy's UKWD was of course physically different to that used by the Luftwaffe. >> >>An example may be seen in the Forsvarsmuseet's Trandum annex north of Oslo. >> >>David > >********************************************************** >David Hamer [email protected] >http://home.comcast.net/~dhhamer [email protected] >********************************************************** -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.1.385 / Virus Database: 268.2.4/282 - Release Date: 03/15/06