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This is an absolutely fantastic website. I have now taken an interest in cryptography and plan on designing my own cryptographic machine. Cheers!
TP < not@guestbook> - Wed Jul 29 06:32:11 CET 2020
Finished buiding a SW antenna following your instructions. Very good reception of the 40 m band. Just starting to experiment
Jose G Parra <> - Thu Jul 16 20:59:17 CET 2020
Toying around with all the cryptograms of Operation Tinker Bell was really a lot of fun and reminded me why working as a signal soldier on a teletype wasn't exactly the most relaxing job. Excellent story, lot's of fun, looking forward for a sequel - maybe this time with audio recordings of number stations or CW?
Alexander W. Janssem < not@guestbook> - Mon Jun 15 16:55:29 CET 2020
Many thanks for you SW anrena recommendations. Thinking in buying a Sangean 909 but also having the chance of buying an old Sony crf-230. What would you suggest?
Josegp < not@guestbook> - Sun Jun 7 16:46:52 CET 2020
Went through the entire "Operation Tinker Bell", deciphered 1-8 messages from the "Enigma Cipher Challenge" and will soon open the 9th message, am sure of it. Don't know about the 10th yet :). An unforgettable experience! A big thank you to Dirk Reimens
Alexey Albov (UEMJ) <> - Sun May 25 10:39:32 CET 2020
DAVE TAYLOR <> - Sat May 16 19:05:22 CET 2020
Crypto box 1 has undoubtedly been the most time-consuming challenge since I first tried it in 2014 until I solved it in 2020.
A hard bone to gnaw on !!, but I have had a lot of patience !!
Highly recommended for those who love difficult challenges.
Rafael Pascual <> - Fri May 15 17:51:48 CET 2020
great site, I am getting information on the mathematical aspects of Enigma.
thank you,
ANtonio Tunin < not@guestbook> - Tue Feb 25 11:16:23 CET 2020
Very interesting, I will visite you again shortly
John DAVID <> - Sat Feb 22 14:50:17 CET 2020
Working Operation Tinker Bell has been the most fun I've had that didn't result removing clothing and having the police show up. Was a KL7 maintenance tech about a hundred years ago and for those of you that have never actually seen or operated one, the simulator is far superior and far more forgiving than the real thing.
Steven Bennett <> - Mon Feb 17 17:52:06 CET 2020
My favorite site for all things cipher, I come back all the time just to read and re-read. Thank you for this incredible resource and all your hard work.
Richard < not@guestbook> - Mon Feb 10 20:19: CET 2020
I like your website, interesting. Personal expiriences would be good to hear.
Tomio <> - Wed Oct 2 05:14:59 CET 2019
Thanks so much for setting up such a great site, with so much valuable information!.
Stefan Claas <> - Tue Sep 17 11:12:27 CET 2019
This is one of the best (One-Time Pad) encryption websites in the world.
Thank you so much for gathering and sharing all the valuable historical cryptographic information mr Rijmenants.
Kind regards,
Ron de Jong
Ron <> - Mon Sep 2 00:36:19 CET 2019
Love the simulators and so very realistic!
Ken < kengraham63@gmail.comm> - Wed Jul 31 11:12:43 CET 2019
What an interesting and carefully made website! Excellent work!
Arnold <> - Fri Jul 19 07:01:03 CET 2019
Just want to thank you for all the hard work on this site. It really is a favorite of mine, and I come back a lot just to look through everything again.
SOOOO much useful information here, all presented in a professional and easily understandable manner.
You are awesome!
Steve < not@guestbook> - Sat Mar 30 22:45:56 CET 2019
Re KL7 sim. Been putting the sim through its paces and been testing what happens when one change in different places is made. Have determined this simulator is actually very very good. In fact I believe that due to the speed of use by running on a PC combined with the relative ease of speed along with the ability for one to be able to literally rewire the virtual rotors and the steppers; this simulator running on a non internet connected pc, I think would be well served in a real world application. Now all I need are minions and my plans for world domination can begin.
Steven Bennett <> - >Wed Nov 7 21:57:04 CET 2018
j'ai utiliser les simulateurs enigma et kl7 ensemble avec un une étape intermédiaire pour tester la fiabilité de la méthode le message passe d'un simulateur a un autres l’étape final kl7.thahk you
baloul karimou < not@guestbook> - Wed Nov 7 20:16:38 CET 2018
merci pour les simulateur c'est travaille de génie la matrice enigma est une matrice d'origine quantique je tente de comprendre la relation c'est très instructif la machine enigma peut passer du classique au quantique(communication quantique chiffré grâce au simulateur.
@000100010001K < not@guestbook> - Sat Oct 20 16:18:33 CET 2018
Thanks for such a cool site! I'm interested in pen-n-paper ciphers and you are one of only two sites I know of dedicated to this stuff.
Girkov Arpa <> - Wed Sep 26 04:11:08 CET 2018
Wow - I thought someone might have tried writing a simulator, but you've owned the thing - well done!
Mark Williams <> - Sat Sep 15 19:50:53 CET 2018
Tnx Dirk for extremely illustrative virtual machine.
I suppose it took a long time to complete algoritm and graphics for it.
Best regards.
Risto in Finland
Risto Tiilikainen <> - Thu Aug 30 10:21:10 CET 2018
Many thanks for setting this up, Dirk. It was really good fun.
To anyone still going through the messages: best of luck, keep at it, and double-check your code :-)
John Davies <> - Mon Jun 11 00:14:57 CET 2018
Thanks for making some cool software !
boB K7IQ
Everett, WA
boB Gudgel <> - Sun Jun 10 05:17:29 CET 2018
Hello from the US and thanks from the 2017 MCTC Cybersecurity Defense Club at MCTC in Minneapolis, MN.
Best of wishes!
Michael Birch <> - Mon Apr 30 16:27:38 CET 2018
Hello from Guam enjoyed reading your SWL pages. Good helpful information :-)
Jim Lampman < not@guestbook> - Thu Mar 15 22:36:19 CET 2018
I found this helpful for helping me speculative on various experimental pen and paper ciphers.
Working on a fractionated vigenere as we speak.
Sarah <> - Wed Feb 14 04:19:08 CET 2018
Love the site Great work. have your Enigma emulator, its just amazing well done to all
OIK <> - Sat Jan 27 20:16:10 CET 2018
I keep coming back to this site again and again. It is one of my favourite sites on the internet. Keep up the amazing work.
Mik Anostalgia < not@guestbook> - Sun Dec 3 01:07:19 CET 2017
I have just found your website via a link from Siemens & Halske T52 - Visited Bletchley Park a few years ago - fabulous site which needs more investment.
Working on Hollerith project at the moment - retired college lecturer of Maths & Computing. Will work through your simulator asap - I loved the stories of how the Poles & Bletchley people found the flaws in Enigma, etc. and used them to their advantage.
Once worked for Friden Singer in Birmingham because their training centre was in Nijmegen (my father lived there so company paid for my trips there).
arnold poos <> - Thu Nov 30 01:50:52 CET 2017
I found your cold war and world war one and world war two era encryption page amazing.
I have not found a better source of online information about old-fashioned by-hand encryption. Very great website.
Edaq < not@guestbook> - Fri Jul 28 03:30:07 CET 2017
Thanks for the tutorial on building an improved, inexpensive SWL antenna system.
KD9BMX < not@guestbook> - Fri Jun 23 18:25:38 CET 2017
Very good simulator. Thank you. Hope you can make this for android!! I will use this with my personaly stuff. Android is mobile and therefore the Enigmasim will do better there. The Enigmaprograms on the "play-marked" is not very good.
Jack < not@guestbook> - Sat Jun 17 06:37:29 CET 2017
Great site, great info, great sims.
As an ex-KL7 user, I thought I'd never want to see one again! It must be embedded in my psyche!
Robin Hague <> - Fri May 5 21:25:18 CET 2017
Great site. Would like to see simulators for Android, though. I have Enigma for Android. Thanks!
S.T. <> - Wed Apr 12 20:42:46 CET 2017
Ik heb deze site al vaak bezocht. Ook dit keer was ik weer onder de indruk. Geweldig informatief.
Tom Lindeboom <> - Sat Mar 25 16:32:20 CET 2017
Mooie site met goede informatie, bedankt.
Jaap Speksnijder <> - Wed Mar 08 21:53:01 CET 2017
A great site that I have used to help solve a geocaching puzzle. I am really impressed by the attention to detail here. Thank you for making this available.
mp < not@guestbook> - Wed Feb 15 10:25:17 CET 2017
Wonderful web site that keeps getting better. I totally dig it.
Allen Francom <> - Sat Jan 14 02:59:16 CET 2017
WoW. Just amazing!!
Please keep running this site for others!
Thank you for your hard work.
Taeil Yi < not@guestbook> - Thu Oct 18 17:49:01 CET 2016
Really appreciated for creating this wonderful simulator of the Enigma machine, and putting so many amazing information together in a website!
Xuanyi < not@guestbook> - Thu Sep 15 05:03:55 CET 2016
Enjoyed playing Tinkerbell. Thanx for it. Fictious cryptographic stories about classical 20th century rival countries(e.g. both vietnam,both Germany, Arab-Israel) will add more spice to the interest of the code-breakers... Thank You.
Arindam Chakraborty <> - Sat Aug 13 16:43:24 CET 2016
Greetings and thax, old crow in US.
Bill <> - Tue Jul 19 16:04:31 CET 2016
First completed Op Tinkerbell some years ago, but thoroughly enjoyed running through it again. Congratulations again on a fascinating project and superb web site and crypto machine simulators.
John H <> - Sat Jul 7 17:48:10 CET 2016
AMAZING !!!! Thank you very much to provide these complete and highly valuable informations about Enigma !!!
Carlos Eduardo < not@guestbook> - Sat Jun 11 03:13:59 CET 2016
I just finished Operation Tinkerbell, and I congratulate you for making such a fascinating and engaging game/challenge. I have downloaded all of your simulators and been impressed every time.
Cameron Jenkins <> - Thu Mar 31 11:28:32 CET 2016
I appreciate your share of information i find beneficial as I delve into security and cryptography. As a student of system security.
Thanks you and will keep in touch on issues of such
Gachunga Wilfred <> - Sun Feb 28 11:42:17 CET 2016
very good enigma simulator
Philipp <> - Tue Feb 23 11:45:36 CET 2016
Great page, started Operation Tinker Bell, this is awesome!
Scott S < not@guestbook> - Sun Feb 14 08:22:12 CET 2016
Love the simulator, fantastic.
Trevor Haagsma <> - Mon Oct 5 03:14:47 CET 2015
Wow, what a gem of a site. So much good information and all explained so clearly. Love the simulators that I have tried so far too. Thanks Dirk!
Edward "SpecialEd" Stahl < not@guestbook> - Tue Jun 23 07:11:29 CET 2015
Love the KL-7 Simulator and the messages! As a former telecommunications tech, with several years of KL-7 and KL-47 usage, this site is great. It helped me to get back to those "days" when I routinely decrypted 1200 group messages, and had a ball!
US Army Warrant Officer Retired
Gerald H < not@guestbook> - Mon May 18 22:24:41 CET 2015
A big thank you, your guide is still the best out there , and from your guide i have indeed constructed my first antenna, and yes my smile was big very big. Have a nice day
Roprepper1 <> - Tue Apr 14 11:17:21 CET 2015
Amazing website, it helped me understand the Enigma machine like magic!! First step into the world of cryptography!!
Sam < not@guestbook> - Sat Mar 28 22:14:25 CET 2015
So many times users forget to say thank you.
I have enjoyed the Enigma Simulator. So THANK YOU.
No reply necessary.
Chuck Fay (USA) <> - Mon Feb 16 15:51:36 CET 2015
This is a wonderful piece of software that's fun to use, even in real-time strategy war games. Thanks for taking the time to make and share this!
Truthseeker4449 < not@guestbook> - Sun Feb 15 22:10:06 CET 2015
Thank you for all the effort you have put into this. Have learned many things from your pages and papers :) Greetings from Croatia
Lupus Vulpes < not@guestbook> - Wed Feb 11 05:00:08 CET 2015
Un immense travail, qui vaut un immense Merci.
duché de Normandie
Christian Normand < not@guestbook> - Sat Jan 31 15:44:19 CET 2015
Hey. Friends Simultor is very good.
Thank you soo Much.
bboyresul <> - Tue Jan 27 18:47:01 CET 2015
Hi Mr. Dirk, I was one of the first to complete Enigma Challenge some years ago, and believe i"m still the oldest..78 next month and the only one from Asia?
Still enjoying it, setting geocaching puzzles and placing the caches by pushbike.
Also using your other simulators.
You have given me so much brain food and resulting exercise I feel I owe you, more than anyone..getting sentimental...??
Very Best Regards
John Angus <> - Tue Jan 27 04:36:49 CET 2015
Accept my thanks for this works and information.
alaa alkhalissi < not@guestbook> - Sun Jan 25 19:15:11 CET 2015
Indrukwekkend! Je wordt stil van zoveel vernuft!
André van Deun <> - Wed Jan 21 10:08:52 CET 2015
Great webpage, with a lot of detailed information and a beautiful Enigma emulator. It was a great surprise. Keep up the good work!
Blacklus < not@guestbook> - Sun Jan 18 20:06:09 CET 2015
geweldige site!!!Ben er door toeval op terecht gekomen maar HEEL knap! en VEEL info BEDANKT!
Ton < not@guestbook> - Wed Jan 14 14:38:04 CET 2015
Thank you Dirk for spending so much time and effort to make your Enigma simulator so great. In addition, your web site is excellent. Keep up the good work.
Best regards,
Jim Rybak <> - Tue Jan 13 16:58:47 CET 2015
Hi Dirk, A wonderfully informative website. I specifically enjoyed the Enigma material and the simulator.
The material on the Hagelin machines and the two simulators are also very good.
Keep up the good work - I'll return to the site often for updates.
Henry Beitz < not@guestbook> - Wed Dec 27 20:22:32 CET 2014
Thank you very much Dirk for this nice Enigma Challenge. It took me a long time to come through but I always had good times in using all great ressources of your website and also by using your outstanding Enigma simulator. The challenge helped me to understand a tiny little bit the gigantic task the pioneers had during the WW2. We must keep in mind that these people didn't have GHz machines we use to crack the messages today to do their job. This deserves our greatest respect. Thank you again Dirk.
Alain Mislin < not@guestbook> - Wed Dec 17 21:34:10 CET 2014
Hallo Dear Dirk, your Enigma-Sim is a very, very nice equipment for descrypt Geocaching callanges, an for my secound Hobby Ham Radio.. thank you for all Enigma-Pictures and Infos Greatings from nr Bonn Hans
Hans, GC:Easystar <> - Wed Sep 17 20:11:41 CET 2014
Excellent and very exciting site and game!
JLS < not@guestbook> - Wed Sep 10 13:18:07 CET 2014
Such dedication. I salute you. vy 73 d3 G4BLN
Rick Fornalsk < not@guestbook> - Tue Aug 5 06:12:02 CET 2014
Terrific introduction the function and history of this fascinating device and to its place in the history of cryptography.
Bill Bosley, K3NN < not@guestbook> - Sat Jul 5 20:15:47 CET 2014
Hi Dirk,
This is a great site! I enjoyed the enigma challenge and the enigma simulator is work of art. Congratulations,
Gavin Melville < not@guestbook> - Wed Jun 18 11:15:50 CET 2014
Wonderful site! I can only imagine how many thousands of hours you have devoted to it. Thank you so much for sharing this fantastic resourse.
Jim C. < not@guestbook> - Thu May 15 18:34:01 CET 2014
Mille fois merci ! Je suis un ancien chiffreur de l'armée française et je viens de télécharger le simulateur de la version CX52. Je n'ai pas connu le modèle avec le clavier.
J'ai aussi utilisé une machine OTAN américaine (pour les messages militaires OTAN) à rotors à contacts électriques (et à déplacement électromécanique) dont je ne me rappelle plus du nom. C'était en 1977. Je vous propose de réaliser ce simulateur également s'il est déclassifié.
Frédéric Chognot <> - Thu Oct 10 23:06:47 CET 2013
I found your Enigma simulator recently and as I've always had an at least casual interest in cryptography, I decided to download it. I had tried another version (maybe an earlier version of yours, I'm not sure)and never got it to work, probably because I didn't take the time to go through the manual. I did this time had have had a lot of fun encoding and decoding messages. Thanks for doing this. I'm going to try out the other simulators as well.
Mark Jensen <> - Sun Sep 8 03:50:09 CET 2013
Hi Dirk,
I like your "Is One-Time Pad History?" paper and am looking around for others like it. If you haven't already found it, check out "Practical, scalable alternative session encryption using one-time pads" for my take on what is to come. Thanks!
Marc Abel < not@guestbook> - Fri Sep 6 23:51:13 CET 2013
Hey Dirk,
wow great site, I love the enigma section. Especially the Enigma Simulator is very useful. Great work and nice that there are still updates.
Christian from []
Christian < not@guestbook> - Wed Jul 24 05:18:44 CET 2013
Hi there, i loved your simulation
I am a leader of a Squadron in a game/sim called "War Thunder" we fly alot of german, and when i stumbled across this sim (enigma), i decided i would use this to encrypt messages!
looking forward to other sims and what-not, TheFurNinja
TheFurNinja < not@guestbook> - Wed Jul 24 05:18:44 CET 2013
What a wonderful site! What a great collection of crypto machine simulators! While I haven't gotten the "Enigma bug", I was very much impressed by the KL-7 simulator. It is the only way now to get a feel for KL-7, which is a lot more interesting than Enigma, and incomparably more secure even by modern standards.
Mouse < not@guestbook> - Wed May 29 06:52:11 CET 2013
I enjoyed very much the Operation Tinker Bell. Thanks for the experience. The new KL7 sim is very interesting and more easy to operate. Thanks for all.
Ubaldo Pioli <> - Mon May 27 05:00:17 CET 2013
Thank you for the time you have devoted !
Loved the One time Pad Info, it was really thorough !
Everything on the site looks impressive and interesting !
Stergios < not@guestbook> - Tue Apr 23 01:24:03 CET 2013
Loved this simulator! I am not really into codes but i have found this whole process of learning how to use the enigma machine and how to read its codes fascinating!
Paul Elliott < not@guestbook> - Tue Feb 26 01:06:10 CET 2013
To this day this is by far the best Enigma simulator available on the Net, Period!
Thank you for sharing all your knowledge.
Dennis < not@guestbook> - Sun Feb 24 12:48:36 CET 2013
An A+ grade simulators, you should proud on them, very nice job.
impeesa5 < not@guestbook> - Wed Jan 30 05:20:43 CET 2013
Very nice job!! Really enjoyed playing with this simulator!
Peter < not@guestbook> - Thu Jan 24 19:03:11 CET 2013
He did a great job creating ALL his simulators! I thoroughly enjoyed them all!
out of 5 stars, I give him 6!
Want to keep this secret! < not@guestbook> - Sat Jan 12 23:49:55 CET 2013
Dirk Rijmenants has done an incredible job in creating his Enigma Simulator, and in organizing the Enigma Cipher Challenge. My wife and I are retired cryptologists, and have actually got the opportunity to encode/decode a message on a real Enigma machine once, while visiting the National Cryptologic Museum in Fort Meade Maryland. We can tell you from personal experience that his simulator both looks, sounds, and performs just like the real machine. Incredible! His website is fantastic as well. What a great free source of information on crypto systems and procedures. Great work Dirk. You are truly an amazing and talented man!
Thank you for all of your hard work, and for selflessly sharing, so that others can learn and grow.
William & Alice Thomas (U.S.N) Retired
William & Alice Thomas < not@guestbook> - Fri Jan 11 11:29:08 CET 2013
Complimenti vivissimi per il sito e per quanto descritto su Enigma.
Vi seguo con passione ed attenzione. Ancora grazie !
Piero < not@guestbook> - Mon Jan 7 22:46:19 CET 2013
Dit is fantasties ongelooflike werk van kommersiële gehalte. Hou so aan man. Dankie vir die bron kode op PSC.
This is unbelievably fantastic commercial quality work. Keep up the good work man. Thanks for the source code on PSC.
Denver Abarahams <> - Fri Jan 4 07:50:38 CET 2013
Looks very interesting to me as former reader of the book The Codebreakers. Excellent!
Jukka Tanttari < not@guestbook> - Tue Dec 18 21:19:32 CET 2012
Hello Dirk, A brilliant effort, congratulations. Your simulator is very useable and is well explained. The history is also very meaningful. Henry
Henry Beitz <> - Sun Nov 7 14:49:40 CET 2012
Thoroughly enjoy your fantastic website. A lot of information not easily available elsewhere. Especially like all the SWL information. Thank you. Best regards,
Hank Lane, KB1JLA
Hank Lane <> - Tue Oct 30 04:55:08 CET 2012
Simply awesome!
I got the enigma bug a while ago but could never find a quality simulator before this one. And this is compatible with the real one! So nice! Good job.
Alex < not@guestbook> - Mon Oct 8 18:03:46 CET 2012
A fantastic piece of work! Thank you.
Jamie Newell < not@guestbook> - Mon Oct 8 10:11:18 CET 2012
This is one of the best Enigma simulators ever. Thanks!
Norbert < not@guestbook> - Thu Aug 16 13:27:06 CET 2012
I'm grateful for your inspiring work! You really make people love Enigma with all their heart...
Beta4good < not@guestbook> - Mon Aug 1 22:21:45 CET 2012
with this excelent site i can only say thanks,thanks, this material will help me solve a geocaching puzzle
John Milk < not@guestbook> - Mon Jul 9 03:06:57 CET 2012
Hallo Dirk
Wat een informatie zeg ,prachtig in elkaar gezet met veel interese eens rond gekeken ,zal zeker nog eens terug komen hier op.
Veel plezier ook op de hf banden als SWL voorlopig.
en welkom op de club van on4anl.
zullen vele intresante gesprekken worden
73 Walter on5wal
Walter < not@guestbook> - Sat Jun 30 15:55:06 CET 2012
Excellent site and info, explanations and simulation software. I enjoyed to decode the enigma messages and learning/using the key procedures, and have now even much more respect for the Polish, British and American de-cryptanalysts in WWII, but also for the German technology and design of the enigma. The site is so well organised and maintained, perfect, I will return.
Leo Kolwijck < not@guestbook> - Wed Jun 27 15:56:22 CET 2012
Awesome simulator! I'm using it for a series of themed geocaches.
Russ < not@guestbook> - Thu Jun 21 22:00:57 CET 2012
ALAN DUCKETT < not@guestbook> - Wed Jun 13 20:36:31 CET 2012
Thank you so much Dirk for putting together this incredible resource! I got the Enigma bug and quickly found your website. I was so inspired by your technical explanation that I wrote an Enigma simulator library in Python. If any Enigma enthusiasts want to take a look, please visit []. I'm still adding documentation and might build a GUI for it someday. But this will allow you to experiment with Enigma codes in Python in any event.
Again, my hat's off to you Dirk for all the time and energy you have put into this great website.
Brian N < not@guestbook> - Sat Jun 2 03:02:53 CET 2012
Very impressive site. Lots of cool stuff.
Mike < not@guestbook> - Fri Jun 1 04:44:15 CET 2012
good software, first good one time pad generator that is out there. Possibly increase in table generation speed.. possibly not.
thanks for the software
afan < not@guestbook> - Tue Apr 10 02:11:42 CET 2012
Thank you for the new version 7.0.3
Johann Vilthomsen < not@guestbook> - Fri Feb 24 14:23:15 CET 2012
A totally absorbing website where the information is not only very well researched, but the story is well told. I am indebted to Dirk for his help.
Keep up the good work.
Fred Searle <> - Wed Feb 15 19:16:01 CET 2012
Thank you so much Dirk. I've been a fan of German WWII ciphers for a while and your Enigma Simulator as well as the other software you write and tools are the BEST there is ! Fantastic work, it is greatly appreciated. I learnt so much in a short time thanks to you. A brilliant website and content ! Well done !
Earl Black < not@guestbook> - Tue Feb 14 02:37:26 CET 2012
First entry in 2012 - the story continues. Thanks for the simulation program and the GREAT fun working on decrypting the 10 tasks. Cool nerd stuff :-)))
This is a hands-on experience that can be understood. All I would still like to know is how the wires inside the weels are soldered.
Max Murdoch <> - Tue Jan 17 16:02:18 CET 2012
I really appreciated the detailed explanations of the hand-ciphers. There are so many programs to utilize them these days that the average person doesn't realize they were designed to be coded/decoded manually.
That said; I notice that all the downloads are Windows machines. I would like to suggest that equivalent Mac versions of programs be captured in the downloads section, if/when they are available. Alternatively; programs in a multi-platform language/script (JAVA, PERL, PYTHON, or JAVASCRIPT) would be even better and very much appreciated.
Gary < not@guestbook> - Sat Dec 24 17:03:01 CET 2011
I'm waiting for a 'Custom Standard One-Time Pads' option in the next 'Numbers secure RNG'.
This option would allow much larger groups (say, 1000 - 1800) than the standard 250 number group.
Great site, keep up the excellent work.
Richard Blaine < not@guestbook> - Mon Dec 12 08:57:54 CET 2011
Thanks Dirk, i love cyphers and Enigma was the greatest non-computerized one ever, thank you for helping me do more wit hmy passion
Jonathan <> - Wed Dec 6 00:14:33 CET 2011
enjoying your excellent site and trying the simulators for the M-209 and the KL-7.
Used both while I was in the Army and this brings back fond memories.
Thank you for your time and effort in preserving these machines for another generation.
best wishes, Maurice Cammack
Maurice Cammack <> - Tue Dec 6 18:45:12 CET 2011
hi dirk,
thanks for the update re the enigma v7 simulator,excellent !!
thanks also for your input re the use of cryptool and assessing the randomness of binary files all the best.
dave smith <> - Tue Dec 6 14:16:31 CET 2011
Hallo Dirk!
Vielen Dank, das du dich seit Jahren um diese tolle Seite kümmers, und uns mit wertvollen Programmen und Informationen versorgst.
Einfach Klasse :)
Andreas Scholler < not@guestbook> - Fri Dec 2 21:56:42 CET 2011
Impressive work. Excellent graphics and very realistic. Congratulations Dirk
Jesus Romero < not@guestbook> - Sun Nov 20 09:37:58 CET 2011
Great site Dirk - I've really only scratched the surface of it so far but lots of interesting things, nicely presented and explained, to take a further look at! I especially like the new improved Enigma rotor tech description pages ! ;-) The Enigma info here was significant in helping me to build my own little flexible Enigma simulator (unix command line application) which has no nice graphics but seems to be working fine. I made it as a programming exercise and a first step towards thinking about a 'virtual bombes' type solution to crack the Enigma code inspired by a recent visit to Bletchley Park (if 'spare' time permits...) so I will be reading more on this site!
Regards/ Henry
Henry Lockyer < not@guestbook> - Wed Nov 16 17:31:33 CET 2011
Very instructive website precise and well realized.
Alexandre TERRAT <> - Sat Nov 5 00:52:25 CET 2011
great sim! great page!
As a Sys-admin/electronics engineer/radio HAM with a passion for all things "tech" it doesn't get any better then this!
Have you ordered your electronic replica of the Enigma yet from the people at bletchley park yet?
The proceeds help the upkeep of the restored Colossus!
paddy lynch < not@guestbook> - Fri Nov 4 18:22:12 CET 2011
Hallo Dirk,
De simulator is geinstalleerd en werkt uitstekend. Prima werk van je. Ik heb altijd belangstelling gehad voor " Bletchley " en alles wat er mee te maken heeft. ( XX, England Spiel, Ultra ). Nu de codes kraken, dat wordt spannend.
Paul Martens <> - Thu Nov 3 18:54:09 CET 2011
a great website dirk ! an excellent educational resource and more!! a great find on the internet. you have done a service to us all who may come now and after us.
dave smith < not@guestbook> - Sun Oct 16 23:42:48 CET 2011
Very nice page and not only program but technical reference of machine is great. Germans were not stupid. They constantly developed their machine. To the 15 December 1938 there were only 3 walzen to choose from 3. It makes 6 possible combinations(3*2*1). After that date 3 walzen but too choose from 5. It makes 60 combinations (5*4*3)I have stopped at message 7 but for a while. I have first unknown stecker in 8 but a took rest and dont have much time like in summer . Sometimes cryptologist can get headache. If i want know in detail how it works i have built paper enigma with every reflecors and rotors. Nice and useful tool.
Krzysztof Mroczka < not@guestbook> - Fri Oct 14 23:09:32 CET 2011
Although I was mildly interested in Enigma before, the availability of the Enigma-e brought it closer to home. After building it, I installed several simulators on my PC, then my laptop and now even on the iPad. Enigma on the go - can you imagine the look on a WWII Enigma operator'sface if he'd be shown such a thing? After visiting a lecture by the Enigma-e designer I started reading up on the subject (do definately read Winterbotham and Welchman!) and bought a stack of books (mostly 2nd hand through Amazon) on the subject nearly one meter high. Haven't quite finished, but working on it...

And then I found the Enigma Challenge. At first I didn't think I would be able to finish it. But Dirks reassuring "You don't need to be a professional cryptologist or maths geek!" convinced me to jump in and I haven't regretted it for a single moment. Not only do the messages bring you an interesting journey of WWII itself, playing with the settings to get to the decrypts proved a very effective way of building up a better understanding of the inner workings of the Enigma. Kudos to Dirk for setting up the challenge! All in all it took me six months from breaking #1 to finding the complete settings for #10. Not a full time occupation of course - you have the luxury of knowing that no lives depend on your decision to watch telly tonight instead of puzzling over a stecker. Enjoy the holiday sun instead of wondering how to tackle a wheel order problem. But those moments of solitary thought, trying to crack another of Dirk's stages in the challenge are sure to teach you more about the way Enigma works (and some of the ways to crack it) than just reading about it in a book. And in the process, it brought to me even more respect for the people at Bletchley Park and in America who did this under the pressure of war, without the technical means available to us today.

Thank you very much Dirk.
deBart < not@guestbook> - Fri Sep 30 09:39:50 CET 2011
Fantastic website Dirk. Very informative and fascinating. Regards, Rob
Rob Stayt <> - Mon Sep 5 16:01:10 CET 2011
I like this program very much, it's a kinda boys dream come true. And så realistic as you have bin there your self.
I'm writing a piece for school about WW2 and this make it perfect.
Thank you
Adam Secher <> - Sat Jun 11 01:08:20 CET 2011
Fascinating! After I read Simon Singh's The Code Book I just had to find a simulator or a buildable kit to go further with the Enigma. Your simulator saved me a bunch of British Pounds! I am a retired school administrator and retired member of the US Coast Guard Auxiliary here in Darkest Arkansas, by the Arkansas River at Fort Smith. Mostly I now do American Civil War reenactments. You can check out that at []
Again, Thanks!
James C. Starbird <> - Sun May 15 02:38:51 CET 2011
Amazing site. Lots of history information. Great job Dirk. Thanks. Keep the good work.
Kestrel < not@guestbook> - Thu May 5 03:52:07 CET 2011
Thanks so much for the time you took in creating/updating this site - the information is very valuable and interesting...keep up the good work!
jh < not@guestbook> - Tue May 3 12:22:51 CET 2011
This is awesome, if one can think that breaking this has changed the outcome of the world war. Thanks for producing this software.
Neoweed <> - Mon Apr 25 13:32:02 CET 2011
Mr. Rijmenants - I thoroughly enjoy your website and your simulators! Thank you so much! You should consider taking financial contributions for your work! - VR, Tom
Tom < not@guestbook> - Sat Mar 19 06:56:12 CET 2011
Wow! This site has so much information, it blows the mind!. I've already leadrned so much! History has always interested me, but this is a tangible way foe me to execute it. What a great reasource! (and FREE to!)!
Lt. Col. Crawley <> - Sun Mar 6 08:04:32 CET 2011
Zeer interessant,mooi in elkaar gezet.petje af!
A.R.Bootsman < not@guestbook> - Sat Mar 5 20:57:48 CET 2011
Hi Dirk. Nice and interesant.. Great job. Good luck. Jan.
Jan <> - Thu Mar 3 11:01:34 CET 2011
Dirks Rijmenants has created a great web page. His simulator is the best, by far, of all available ENIGMA simulators. The historical information and supporting information for the ENIGMA machine are outstanding.
JIM RYBAK < not@guestbook> - Thu Feb 17 16:56:22 CET 2011
What a fantastic site! I've been interested in numbers stations since I first heard one as a kid in the 70s on a shortwave radio I had brought back to life (learned how to test and replace these things called 'tubes'). I've never found more than a few bits of information about how one-time pads worked, but never how they constructed the messages for broadcast. I am a kid in a candy store here! Thank you so much for sharing in such a well structured and entertaining way. We greatly appreciate your work and passion!
Toodles old bean.
Curt <> - Thu Feb 10 03:54:08 CET 2011
Great bit of techie nostalgia. The software is great stuff. Pip, pip
Toodles old bean.
AL Brims < not@guestbook> - Mon Jan 10 21:55:56 CET 2011
Great website, with a lot of historic references. This makes cryptography even more interesting! The software I like the most is ATOMIX, but can't find information or historic references about it on the Internet. Is it only a virtual machine?
Rocky < not@guestbook> - Thu Nov 18 20:04:48 CET 2010
Thank you for the wonderful and extensive web site you created and the simulators are nothing short of amazing. I've downloaded and spent time with all of them.
This is the best collection of information I've seen in one place since an uncle sent me a copy of the Code Breakers in the mid 60's. I've been hooked ever since and deeply regretted not getting to work on codes and cyphers full time throughout my life.
Thank you again. I come back to your website again and again over the years.
Henry Roberts
Henry Roberts < not@guestbook> - Wed Nov 17 02:02:39 CET 2010
Great website!
Ronald Adamse <> - Fri Oct 8 00:34:16 CET 2010
Excellent site, my compliments.
The cryptographers were among the very brightest people of all time. The story of their hard work and success is so very impressive. My thanks to them for the Allies’ lives that they saved.
Faultersack < not@guestbook> - Sat Sep 18 22:44:53 CET 2010
OMG, I LOVE YOU!!! >_> Ok, not really. But, I do love how easy you made enigma to understand. Thank you!
Aaron < not@guestbook> - Tue Aug 24 18:09:47 CET 2010
The first Enigma machine was built in 1404, albeit with just 2 rotors & finger powered, but exactly the same principle.
Excellent site.
Republic of Armenia
Ardavast Vahani Avedissian <> - Fri Aug 20 09:53:12 CET 2010
Excellent site. I recently visited Bletchley Park and saw enigma machines, collossus and the bombe and was totally bowled over as to how complicated it was.
I tried writing my own Enigma in VB to get a grasp of it and after a day spent getting the wheels to step properly i got totally lost in how to actually encode a letter! I could probably build a real machine faster as i'm an engineer but i'm afraid to say i gave up and downloaded your fantastic example, well done.
Dave Kearley <> - Tue Jul 13 10:57:39 CET 2010
Thanks for the cipher machines simulators. I really like the realism of the C-52 and Enigma simulators. I learned a lot from your site about crytology. Again thank you very much
Audie Geronimo <> - Tue Jul 6 06:37:08 CET 2010
Dear Mr. Rijmenants: Thank you very much for your excellent and unique cryptic work. I’m an amateur hamradio operator, and always looking for secrets codes and messages in the radio spectrum. It is a privilege to visit your illustrative webpage. Best regards, Angel-KP4EU.
Angel L. Saavedra <> - Mon May 24 04:57:52 CET 2010
Klasse und gut gemachte Webseite. Freundliche Beantwortung der Anfragen. Weiter so.
Klasse en goed ontworpen webpagina. Vriendelijk antwoord op de vragen. Keep it up. Over een bezoek zouden we blij. []
Karsten ( remove XYZ ) < not@guestbook> - Sun May 23 07:35:01 CET 2010
perfect stukje werk op deze site, veel geleerd in korte tijd, neem rustig de tijd om alles door te nemen en te proberen. toch wel knap dat ze dit toen al konden maken...
eduard <> - Sat May 15 03:35:48 CET 2010
Knappe site waar nog vele een voorbeeld aan kunnen nemen. Alles wordt duidelijk uitlegt.
Ik heb hier al heel wat bijgeleerd.
GEERTS FRANK < not@guestbook> - Thu May 13 21:04:09 CET 2010
This is truly amazing. I have learned more in the last 3 hours than I ever thought I could. Thank you and I am looking forward to a challenge!
PAllen <> - Mon May 10 23:04:34 CET 2010
With a lot of help from Dirk I finaly "solved" the Enigma coin puzzle. My next problem is to try to export beer from Sweden to Belgium. Not easy since Belgian beer tastes much better then Swedish. But I will have a go at it :-) Thanks for an outstanding simulation program.
geoskane < not@guestbook> - Sun Apr 18 22:00:14 CET 2010
Thanks a lot for that great piece of software which allowed me to decrypt a message I received with a Geocoin - but only after Dirk helped me a little with the setup of the program. Cheers! :beer:
Friedemann Schorer < not@guestbook> - Mon Apr 12 20:17:53 CET 2010
The best edutainment on earth in my humble opinion. The Enigma and the instructions leads you into a fascinating world of history, decryption and solving puzzles even in the geocaching society. Thanks Dirk for an excelent job, I wish I had more time and IQ to really grasp "it all". With your help I at least I know the basics of the Enigma.
Mats-Ola Ekberg <> - Wed Apr 7 20:37:29 CET 2010
As a freelance signals security consultant, I owe you guys my job. If I wouldn't have used this site during college as a recource, I wouldn't have graduated. Thanks, dirk. I owe you one, man.
Stephen K. Rathje <> - Sun Feb 28 20:29:32 CET 2010
IVAN DIB BUCHALA <> - Thu Feb 25 14:42:47 CET 2010
Nooit gedacht nog eens iets van de Kl-7 terug te zien. De simulator is geweldig en ik kan uit ervaring verklaren dat deze de werking van de echte Kl-7 volledig simuleert. Oude tijden herleven weer!!
Richard van Binsbergen < not@guestbook> - Sat Feb 20 20:02:58 CET 2010
Das ist ja erste Sahne!
Tom Flaherty < not@guestbook> - Sat Feb 13 11:01:38 CET 2010
Thanks for creating this remarkable, fascinating, and educational program.
Steve Cator < not@guestbook> - Fri Feb 12 00:27:56 CET 2010
I am quite pleased, not to mention relieved, to have completed the Enigma Challenge. I learned a lot about Enigma in the process, and improved my programming and statistics skills also! You have a great collection of links, and the Enigma simulator is a magnificent piece of work. Met vriendelijke groet. Jerry.
Jerry McCarthy <> - Fri Jan 8 11:11:37 CET 2010
Thank you for making available all of these hard to find programs and the great information that goes with them.
Frank Merlott < not@guestbook> - Mon Jan 4 03:33:08 CET 2010
Excellent website and some fine software applications. Yours is the best OTP utility out there.
George Smiley < not@guestbook> - Tue Dec 8 12:27:55 CET 2009
I came across your website via a link in Wikipedia. Good job!
Ashaadi Fandzuri Adnan < not@guestbook> - Wed Nov 25 10:03:41 CET 2009
That's an excellent Site, thank you very much! Question: I am searching for a simulator of the M2114 Model. Where can I find it? Or is the M3 or M4 the same? I need to decrypt a message of a quiz. But they mention an 'inner' an an 'outer' ring. But your simulation only has one ring. Who can help? Thanks!
Martin <> - Sat Sep 26 10:11:07 CET 2009
Congratulation, keep this excelent work!
Such amount of information about many classical cipher is really hard to find in one site alone.
Daniel <> - Sun Sep 20 02:06:57 CET 2009
Excellent work,Excellent information, Excellent simulator! Feels very real. Thanks.
Pablo Merighi < not@guestbook> - Mon Sep 7 00:23:10 CET 2009
Very good work. Well done!
Jeremy Gorsline < not@guestbook> - Tue Sep 1 21:47:33 CET 2009
Thanks for a fantastic webpage and a very stimulating challenge. It have given me alot of amusement, and some gray hairs too;-) and a fantastic historic trip through ww2.
Martin Eklöf < not@guestbook> - Tue Aug 18 00:40:28 CET 2009
Excellent. Good Simulator. I'll learn this simulation. Excellent 5 stars.
Chudry <> - Fri Aug 14 00:38:16 CET 2009
I just wanted to let you know that this is such a cool place!!! Love it!
Anders Samuelsson < not@guestbook> - Wed Aug 5 19:15:37 CET 2009
hoe kan het dat ik deze site nu pas zie.
Geweldig alles bij elkaar, wat een werk. Zeer mooi gedaan!
plens < not@guestbook> - Tue Jul 28 20:10:02 CET 2009
Het so pas David Kahn se Codebreakers gelees en was op soek na verdere inligting oor OTP. Vind toe jou website. Verstommend en fantasties!
John Blanckenberg < not@guestbook> - Sat Jul 11 13:00:16 CET 2009
Excellent information. I enjoyed reading it and learned a lot. Thanks!
Karl Schantz < not@guestbook> - Wed Jul 8 21:38:50 CET 2009
What a fantastic site. I've been reading pages and playing with software for hours and I've only just scratched the surface. So many valuable links too. I wanted to let you know that your work is very much appreciated. I'll be a regular visitor from now on.
Thank you.
MikiStrange < not@guestbook> - Mon Jun 29 12:51:04 CET 2009
Hey bedankt voor de bruikbare informatie voor mijn PWS
Niels < not@guestbook> - Mon Jun 30 09:27:18 CET 2009
Keep up the good work!
Sam Snead <> - Sat May 30 02:12:44 CET 2009
Absolutely amazing work! Amazing software simulations, extremely informative. The best site!! Thankyou for all your hard work and enthusiasm it is truly appreciated.
Earl < not@guestbook> - Fri Apr 24 23:35:07 CET 2009
Mijn hobby is geocaching. Dat houdt in dat ik dikwijls puzzles op moet lossen die me naar een cache leiden. Een bevriende geocacher uit Denemarken had een "Enigma" puzzel voor me. Mede dankzij jouw site en de gave simulator was ik in staat voor hem de puzzel op te lossen! De volgende twee "mystery" caches gaan over de Fialka en Hagelin machines. Gelukkig heb je ook voor een van hen een simulator. Voor de Fialka heb ik een andere site gevonden. Bedankt voor de "indirecte"steun!
Ans Wouters <> - Mon Mar 23 13:56:32 CET 2009
Diese Seite ist ein echter Schatz, für jeden Hobbykryptologen.
Der Autor ist sehr hilfbereit, und erklärt z.b bei bedienungsproblemen zu einer Simulation, geduldig und gut verständlich, wo das Problem ist.
Auch die anderen Programme wie der One Time Pad sind gut erklärt, so hat man neben dem Programm auch gleich sehr viele Informationen, ohne erst viel suchen zu müssen.
Auch allgemein befinden sich viele Informationen über Kryptografie im allgemein (unabhänging von den Programmen) auf der Seite.
Die Seite ist wie ich finde sehr gut gepflegt, und übersichtlich gehalten.
Danke an dem Author für diese tolle Seite!
A.Scholler < not@guestbook> - Mon Mar 9 17:04:43 CET 2009
Dirk, hartelijk dank voor deze fantastische en informatieve site.
Johan Visser < not@guestbook> - Sun Feb 1 18:08:11 CET 2009
Ik doe zelf studie naar deze codes ga op korte termijn mee doen aan het CONET PROJECT met mogelijk doel om dit te decoderen wat nog best een knap stukje werk is.
Tevens vind ik deze site erg goed in elkaar gezet
Met vriendelijke groet
Michel < not@guestbook> - Wed Dec 3 16:19:04 CET 2008
Thanks so much for your amazing work! My fisrt novel (hopefully to be published in late 2009) made extensive use of the Enigma Sim. I will sign again when it is released to let you know.
And thanks for your kind reply to my email. Keep up the great work.
Callum MacAlister < not@guestbook> - Thu Nov 20 23:16:56 CET 2008
Thanks! Very intresting information about Enigma.
mgbada lai <> - Thu Sep 9 12:30:44 CET 2008
Excellent site. Found a lot of useful info here, and have had a lot of fun using the hands on approach with the Enigma Simulator.
Thanks so much for providing all of this for us!
Effigy < not@guestbook> - Fri Sep 19 10:24:03 CET 2008
Great stuff!
SvenP <> - Thu Sep 4 18:34:51 CET 2008
Hi Dirk,
thanks for compiling lots of information on enigma and cryptography! Encryption is a fascinating topic and there is always a lot to learn. All the best! Christian from Austria
Christian Fiedler < not@guestbook> - Wed Aug 6 20:40:02 CET 2008
Thanks! Very intresting information about Enigma.
Jani < not@guestbook> - Wed Jul 16 14:41:52 CET 2008
Hi Dirk, Thanks for replying to my email.(i could not resist sending it in code). Great sim, enjoying learning about enigma etc, your pages are very helpful. Regards John.
John Walsh <> - Wed Jul 2 17:47:22 CET 2008
I love your website, it's great for my research paper over WWII cryptology. However,if you'd like to be accredited more often it might be good to have information on how to cite this website.
Just someone doing a paper < not@guestbook> - Sat May 10 22:43:08 CET 2008
Dirks, via via kwam ik op deze site en mijn belangstelling was gelijk gewekt. Heb de site onmiddellijk bij bij nijn favorieten in het mapje "verbindingsdienst" gezet, zodat ik de site eens rustig kan bekijken. groeten joop volkert
joop volkert <> - Fri May 2 16:49:11 CET 2008
Thank you very much for tha information you give at these pages. The Enigma Challenge is amazing! I hope I'll be able to finish it... These pages are a must for various interested in the different branches of Sciences and humanities... Yes, indeed, they are!
Rafael Padilla <> - Mon Apr 21 12:27:57 CET 2008
Great Job! Thanks for it!
Mateusz Wisniewski <> - Sat Mar 15 17:20:39 CET 2008
Dirk, the enigma simulator works like a dream. After trying to make a simple one myself, I know how tricky it is. The Enigma Challenge is simply great, everything is made with great eye for detail and the plaintext stories are in the same league. Solving all 10 challenges kept my grey matter (and my laptop) busy for weeks! Thanks for this great experience.
Frank Inklaar < not@guestbook> - Sat Mar 15 09:33:10 CET 2008
Dank-u vor de website
Samuel Zara <> - Sat Mar 8 19:25:41 CET 2008
I came to your site for the code, excellent.
Thanks for honoring a great American soldier.
Ed Taylor < not@guestbook> - Tue Mar 4 20:24:17 CET 2008
oostende 25/02/2008
U hebt fantastisch werk gemaakt........ Ik heb er over gelezen... Ga proberen er wijs uit te geraken... Boeiend tot en met...
Robert Lenaerts < not@guestbook> - Tue Feb 26 00:04:47 CET 2008
Hi Dirk - you managed to produce a fascinating site; thanks a lot.
Ulli < not@guestbook> - Wed Jan 23 21:16:04 CET 2008
Thanks! Great job. I haven't had so much fun since Orbiter simulation. \m/
Jakub Warzecha <> - Tue Jan 17 11:57:39 CET 2008
Well Well... What can i say? Dirk, you leave me speechless... I havent seen such perfect simulators.. but more than that, i havent met or known anyone who's so so so genuinely helpful and concerned for people!!! Dirk... You're the man!!! :)
Saira Junaid <> - Fri Jan 11 05:35:41 CET 2008
guys like you recovers my belief in internet
bruno, Melbourne
bruno < not@guestbook> - Mon Jan 7 04:50:06 CET 2008
Great work, Mr. Rijmenants!
It is wonderful that some people have such incredible bags and spend a lot of their free time to share results of their hobby-work with others! The ciphering area isn't well known to the wider public but your website surely helps to enlarge this knowledge!
Burbon < not@guestbook> - Sun Dec 30 20:46:33 CET 2007
You did a great job! Thanks
Kamil. P < not@guestbook> - Fri Dec 28 13:38:10 CET 2007
I had a programming challenge at school today, and one of the tasks was a much simplified Enigma simulation. I failed miserably, and starting reading up about rotor machines. This website is a great source of information.
James Stanley <> - Fri Dec 14 20:37:42 CET 2007
Hi, came across the site only a couple of days ago and already I'm hooked. Great information (fascination), great quizes, all round great site.
Derek Smyth < not@guestbook> - Sun Dec 9 19:48:16 CET 2007
Fantastic website! The ENIGMA simulator in particular and the Challenge are both outstanding. Thank you very much for creating such a good piece of software.
All the best 73 de Philip G0ISW
Philip G0ISW < not@guestbook> - Thu Nov 29 18:44:07 CET 2007
Damn fine program you have made here. Only had one problem and that was half the lights dident light up, I probaly installed it wrong as it worked fine once i re-installed, So realistic the light bulbs went :P
Tengu < not@guestbook> - Sun Oct 28 00:15:54 CET 2007
Hey, cool site! Very cool software. It's a great way to help preserve history and make it available to those who are curious. Thanks!
Aaron < not@guestbook> - Mon Oct 22 05:19:40 CET 2007
Finalmente qualcuno ha fatto chiarezza su una materia "oscura"
Mister_xyz <> - Wed Oct 9 22:03:08 CET 2007
I was just wondering the other day, what is the total keyspace of ATOMIX machine? :)
Other than that, an excellent site, even better simulators and absolutely number one when it comes to reference :)
Tomaz <> - Sat Oct 5 19:00:54 CET 2007
Thanks for the challenges. I've been hooked since I found your page, and couldn't put them down until I finished them.
Great Enigma sim, and a ton of useful info about crypto machines too.
A pleasure to surf.
Javier Marcelo < not@guestbook> - Sat Sep 29 21:07:10 CET 2007
Nogmaals mijn complimenten. Ook de codebook tool is erg leuk gevonden, en zit goed in elkaar.
Canovaro <> - Tue Sep 18 16:23:24 CET 2007
A truly fascinating, informative and absorbing site. The best Enigma simulator I have ever seen and used. The challenges are varied, imaginative and challenging! Many, many thanks. Terry Dalton
Terry Dalton < not@guestbook> - Mon Sep 17 15:22:57 CET 2007
Excellent site, Especially the challenges,
Be a tough job to stop until i have cracked all the codes. Plenty of useful information on cryprographic techniques.
Dan Goldsmith < not@guestbook> - Tue Sep 4 16:39:02 CET 2007
Your website and work are great!! It´s hard not to get completeley hooked while browsing your site (my computer is now running Stefan Krah´s M4-project client program).
The Enigma simulator is fanatstic. Thank you!
Fenimore < not@guestbook> - Wed Aug 22 16:06:21 CET 2007
Great! I use it to demonstrate codes in my computer education class.
Charles S. Roaten <> - Tue Jul 24 01:49:52 CET 2007
Your site is really perfect as your simulatores
Piotrrze < not@guestbook> - Tue Jul 17 11:07:29 CET 2007
Your *the* man... And so is your website!
Robert < not@guestbook> - Mon Jul 2 16:38:11 CET 2007
Great Work! Thanks a lot for the programms.
Randolf < not@guestbook> - Sun Jul 1 14:12:38 CET 2007
Thank you very much for this great simulator!!
Stanko <> - Sun Jun 10 15:12:02 CET 2007
I just came across your SECOM cipher when looking for usable pencil and paper ciphers.. great piece of work.
Tavy < not@guestbook> - Tue May 1 07:02:14 CET 2007
By far the most professional simulator out there. Keep up the good work! The kids love playing with it and we have used it to teach how the machine works.
John Drake < not@guestbook> - Sat Apr 28 02:38:47 CET 2007
(From Cremona - Italy)
This is a very great work!
Amazing simulator and very clear, detailed and complete all the entire site including photos.
Thank you very much!!!
Marco < not@guestbook> - Wed Apr 25 22:22:17 CET 2007
Hey! whats up. I like your site, i use it for my school papers, as well as some other guy that signed
Mike <> - Tue Apr 24 18:21:06 CET 2007
I'm presenting a school paper on Enigma and it will probably only have your website as a reference. You have covered the subject completely. Thank You!
Joe Duran <> - Sat Apr 14 12:48:22 CET 2007
Could it be possible to add an option, to automatically create keys (from a passphrase) for the ACX crypto pad ?
Robert Bruce < not@guestbook> - Tue Apr 10 16:15:03 CET 2007

Note from Dirk: the Crypto Pad key has to follow some important rules to ensure a high level of security. Creating a key from a passphrase that follows these rules would be difficult (for instance, the bit setting of each array must be truly random and that's hardly the case when derived from a phassphrase).

Thanks so much for this nice site. Very good work
Best regards from Madrid-Spain
Jorge Ramio <> - Sat Mar 10 20:53:18 CET 2007
Love the site and the simulator. My "spy kids" will love this thing. Only problem is that the Help file no longer opens on Windows Vista as it is in an obsolete format. Any chance we can get an updated version, or an HTML with the same data on the web?

Mark Jeffrey < not@guestbook> - Tue Mar 6 17:33:42 CET 2007

Note from Dirk: A new Enigma version 6.4 is out and includes an improved pdf manual with detailed pictures, schematics and other information.

Very interesting website!
Well done
(Like the Enigma simulator as well)
Andrew Savin < not@guestbook> - Sat Feb 3 20:36:10 CET 2007
First I found your site, because I was just looking for an enigma simulator, and learn how this famous machine was working. But than I read about your challenge, and saw in the table of honor that quite a lot other guys are interested in this stuff too. This challenge was definately the reason to get deeper and deeper in the secrets of the Enigma-machine and code-breaking software. Beacause of Dirks creative riddles (written by hand on paper, interesting stories) it was an exciting advanture to finally solve every 10 Messages. This shows in a perfect way how a very theoretical and "boring" theme like encryption can be made exciting for everybody (easy 1st message, getting more and more difficult).

Congratulations Dirk, sngiteerg morf airtsua, Thomas Mueller :-)
Thomas Mueller < not@guestbook> - Thu Dec 28 20:23:41 CET 2006
Hey People!
This is very nice site!!!
Forever Rules!
Pananto <> - Fri Dec 22 19:29:03 CET 2006
The Engima emulator is outstanding! I'm going to explore more of the site.
Brandon < not@guestbook> - Fri Dec 22 16:32:53 CET 2006
Cool site! Never learned so much about enigma, cyphers and WW2.
Your challenge was great, too (interesting content,...).
And thanks for the Enigma simulator and the codebook tool!
Christian <> - Fri Dec 15 17:09:30 CET 2006
This is one of the most interesting sites I've visited over the net! Congratulations!
Mauro Chamani <> - Wed Dec 6 02:48:58 CET 2006
Thank you for your work. It is quite fun to make a riddle with the settings (only "enigma says <all settings for it>" on a piece of paper) and the code anywhere else. they've to find out.
Sebastian Loscher <> - Tue Nov 28 23:03:31 CET 2006
Loved the history and intrigue.
Harry Brugmans (geocaching: BearGPS) < not@guestbook> - Sun Nov 5 23:04:43 CET 2006
Awesome, we are learinin about this in schjool
Joe Barnes < not@guestbook> - Sat Oct 28 19:39:24 CEST 2006
Awesome job on the Enigma Simulator...Great Web Site...will be passing this site along to my kids school for a looking at by they're teachers.
Iceman < not@guestbook> - Wed Oct 25 21:56:18 CEST 2006
Hi Dirk
I am a former Merchant Marine Radio Officer.
Worked for German and British Owners from 1978 to 1996.
Retired before technology kicked me off.....
Much interested in Radio Comms history, found your page very educational and helfpfull.
Thank you very much for your good work and efforts to enlight all of us.
10 out of 10 for the simulator.
Best regards
Waldo from Barcelona/Spain
Waldo < not@guestbook> - Mon Oct 16 18:30:07 CEST 2006
Hi Mr. Dirk. I'm interested in History of the WWII and Languages.
You did a really good job doing this simulator. Keep it up!
Welton <> - Wed Oct 11 07:00:31 CEST 2006
I like the simulator. The help file shows how the "operator's key sheet" would appear. In addition to the existing "Enigma Settings" display, would it be possible to add an option to display the Enigma settings in the same format as the "operator's key sheet". This would add some historical realism.
Robin Snyder <> - Sun Oct 1 15:07:52 CEST 2006
Er moesten er meer zijn zoals jij...schitterend !
Pierre <> - Tue Sep 26 21:42:18 CEST 2006
Great site about crypto. Your machines are great.
Hope you continue to make more simulators.
Jim Smith <> - Mon Sep 25 15:10:31 CEST 2006
Great web site. I love the Enigma Challenge, even though I am late to the game. The simulator is the best Enigma sim I have seen.
Dave < not@guestbook> - Fri Sep 15 20:26:49 CEST 2006
Mooi gemaakt Dirk.
En interessant.
Peter ON4AGP < not@guestbook> - Wed Aug 30 11:40:00 CEST 2006
Proficiat met de website. Als ex-onderofficier van het 6e bataljon transmissietroepen in Ludenscheid had ik enkel ervaring met Maplay, Slidex en Hertzbundelverbindingen...
Geert <> - Sun Jul 30 15:50:28 CEST 2006
Tolle Internetseite, großartige Challenge, sehr gute Enigma-Simulation.
Nochmal vielen Dank für die Mühe all das Material zusammenzutragen. Mir hat besonders die realistische Gestaltung der Challenge gefallen. Man kann viel über die Enigma erfahren, auch die Links sind sehr interessant!
Heinrich < not@guestbook> - Wed Jul 5 07:07:13 CEST 2006
Zeer duidelijke beschrijving van de Enigma
Jozef Kerkhofs <> - Wed Jun 7 01:26:32 CEST 2006
Absolutly brilliant! What about starting an international user group dedicated to sending and decoding messages using your sim?
Charlie Delta Hotel < not@guestbook> - Tue Jun 6 15:51:16 CEST 2006
Zeer duidelijke beschrijving over de Enigma, ook zeer leuk verteld,
heel mooi!!
Ronald Boers <> - Mon Jun 5 12:17:50 CEST 2006
Thanks for sharing Amanda Pinson's story. May she rest in peace and never be forgotten.
Chris < not@guestbook> - Thu Jun 3 15:06:24 CEST 2006
Great simulator. very in depth and complicated!
scott <> - Thu May 18 06:01:45 CEST 2006
Fantastic program. Helped me tremendously in developing/tweaking a calculator project.
G Bucher < not@guestbook> - Wed May 3 09:14:19 CEST 2006
The Best Enigma Simulator i ever tried. Great work.
And thanks for the codeBook tool
Hershall < not@guestbook> - Thu Apr 13 22:36:56 CEST 2006
Both simulators, the Enigma and the M-209, are great programs! The graphical interface is very realistic! Doing geocaching, some mystery caches in Quebec use those machines so I got no choice and had to learn how they work! Thanks again Dirk!
Alain <> - Tue Apr 11 14:49:35 CEST 2006
Fascinating site. I came across it as its needed to solve a puzzle geocache near Liverpool in NW England. See for details
Phil Wright < not@guestbook> - Thu Mar 30 13:10:41 CEST 2006
Ukw D is a rare artifact now but in 1944 it was very used. A lot were destroyed after the war (The US sold the Enigma to others countries but not the ukw D and the Uhr box because it was more difficult to crack them and US wanted to spy others countries)
John < not@guestbook> - Tue Mar 28 21:05:19 CEST 2006

Note from Dirk: Thanks for the find of the articles John! Very interesting! Lucky for us the D still came to late to change odds :-) Maybe stuff for a future project, hard to incorporate all different things in one sim. And we even didn't mention the Railway and Abwehr Enigma. But if a message surfaces, it's mostly Wehrmacht or with some luck a Naval one. So, the current sim can do the job. Frode Weierud from CSG has several different types of Enigma, great site!

It's not true reflector D was very used in Luftwaffe since 1944
look at Cryptologia articles :
part I:
part II:
part III:
John < not@guestbook> - Tue Mar 28 21:01:45 CEST 2006
I would be great if you could implement the UKW D with the 3 rotor Luftwaffe Enigma.
Hin < not@guestbook> - Mon Mar 27 11:27:45 CEST 2006

Note from Dirk: I didn't add the D-reflector since it's very rare and seldom used by the Luftwaffe, just as the Enigma Uhr box. Nice tricks, but they came to late to make a difference.

That's by far the best looking and most interesting/informative Enigma sim I've seen! I've just updated my "Further Readings and Fun" ( ) page of my "eMail Encryption for the Lazy" site to link to your site.
Thanks for providing the site and the sims!
Jörn < not@guestbook> - Tue Mar 14 20:41:04 CET 2006
Cool Work. Congratulations..
This work has historical and practical value..
Tassos Z < not@guestbook> - Sun Mar 12 21:42:42 CET 2006
Great idea and nice toy!!! Thank you.
Sönke Peters <> - Mon Mar 6 18:41:19 CET 2006
Dirk's simulator is the only tool available to imitate functioning of an extensive Enigma family rather, than, like its competitors, single family member. Based on the thorough research, it behaves exactly like its original.
I'm using it extensively while deciphering original messages as well as imitating BP codebreaking operations.
Dirk, you know from my mail the only detail missing, hope some day you will find enough time to add this function.
Marek Grajek < not@guestbook> - Thu Feb 2 22:25:26 CET 2006
Very good simulators. Both the Enigma and the M209 work with WINE under Linux.
Harald Arnesen <> - Sun Jan 29 16:06:20 CET 2006
Enigma Codebook Tool is the perfect combination to learn properly to run the Enigma Machine. Tankyou for these tools and go ahead!
Funken < not@guestbook> - Sat Jan 28 16:49:12 CET 2006
A very good and real looking ENIGMA simulation,
Maxx <> - Tue Jan 24 13:22:42 CET 2006
Fantastische site! Geweldig zo'n heldere uitleg over deze codeermachine....
Vincent < not@guestbook> - Mon Jan 23 14:11:22 CET 2006
I was searching the Internet for information about Enigma to make/program one by my own, and found your fine simulator. I don't think I can do better, great work! The best we can found! Puzzeling your VB code give me a great reading evening and some fine 'aha moments', and even more exiting was reading the article in your weblog about 50 cents quantum security, lets's try this at home!
NivaRo < not@guestbook> - Wed Jan 18 21:44:10 CET 2006
Heel erg interesant, ik heb gisteren een film gezien over de enigma code en wat the Britten deden om het te kraken.
Dank U voor de kans om nu zelf met de Enigma machiene te spelen.
Fantasties stuk werk.
Richard Dekker <> - Tue Jan 17 04:09:06 CET 2006
Of the various Enigma Simulators I have seen, this is certainly the best. The Enigma simulator has helped bring this fascinating subject to life for me, and I am most appreciative for Mr Rijmenants' work, and for sharing it with everyone.
S. Brannan < not@guestbook> - Sat Dec 31 09:31:31 CET 2005
Ik vind dit een schitterend idee en initiatief, erg origineel, ondanks dat enigma meer dan 60 jaar oud is!
maurits marain <> - Sat Dec 17 14:06:54 CET 2005
A very great work. I used this programm to teach some aspects of cryptography to my students.
Marcio Nunes <> - Sat Dec 3 20:42:16 CET 2005
Excellent site and simulator. congratulations.
Marcio Pohlmann < not@guestbook> - Tue Nov 29 14:39:45 CET 2005
Exellent site!
Very useful for all who use the Enigma-E electronic enigma.
Thank you for all your efforts.
Cheerio, Marcus PE1RRT
Marcus Simons < not@guestbook> - Thu Nov 24 21:41:28 CET 2005
Well done! It's a pleasure to use. I will be sharing this cool simulator with friends for sure.
Mark Thibault < not@guestbook> - Fri Nov 18 07:47:58 CET 2005
Really a great Simulator! Fantastic! But at the moment i still dont know right about, how the Code for each message is created/read. Big praise!
Andyfrey < not@guestbook> - Thu Nov 17 23:38:57 CET 2005
Great simulator! Next time how about the Kurzsignalschlussel or Wetterkurzschlussel simulator?
Alphonse <> - Thu Nov 17 06:17:16 CET 2005
Excellent simulator. Too bad that the codebuch generator available elsewhere doesn't take into account the Gamma and Beta rotors. We use this in the Wolfpack League Atlantik! Kampagne.
CaptSquid <> - Sun Nov 6 04:03:04 CET 2005

Note from Dirk: I just wrote my own codebook generator, the Enigma Codebook Tool is now available for download!

This simulator is a terrific device. Well designed and highly addicting. On top of that Dirk is a very helpful person in explaining questions that come up. Thank you!
Jan-Bert Bongaarts <> - Thu Oct 6 12:43:47 CEST 2005
Je viens de lire le livre de Hugh Sebag-Montefiore sur ENIGMA - THE BATTLE FOR THE CODE. Votre programme est parfait comme illustration. Une merveille!
Charles < not@guestbook> - Sat Sep 24 18:42:51 CEST 2005
Excellent work, old chap! It's come in quite useful for me!
Macavity <> - Mon Sep 19 20:50:44 CEST 2005
Impressive website sir, and I haven't even tried the simulator! All this reminds me when I was a school pupil coding messages by mail with a friend. Good old days, I always came up with the best ideas for codes.
I wonder if we've had an Enigma...
Andres Serrano-Jordan < not@guestbook> - Sat Aug 27 21:38:01 CEST 2005
You have done a great job, my son! :) Dirk! I am really glad we did manage to "meet" again, thanks to bloody Internet. You know, we both are more soldiers than computer geeks, we prefer to stay in the trenches rather than in the nice and warm cities. I can still remeber all of you guys, my lovely "Motorola team", the UNTAES communications heart! I wish you all the best and please, never get lost again.
Shake your hand, old dog! All the best to you.
Alex Karelin (Russian Marine Colonel) <> - Wed Aug 3 09:30:19 CEST 2005
Hey buddy what a great idea have you done!!
Im an architect working in foreign country, im entertaining my self recently in cryptography and I landed on your site,
Im downloading at the moment the enigma & M 209 cant wait to see what it got...
thanks and more power...
Ernie <> - Sun Jul 31 21:08:01 CEST 2005
the enigmasim is the best sim ever! i dont understand the m-209 but it looks great too :)
P.S. my email adresse is real! try it!!!
Necr0 <> - Sun Jul 17 19:11:12 CEST 2005
I just downloaded from your site, havent' even tried it yet but I'll tell you that this looks like a marvelous toy. Thinking about turn based strategy or tactic games, this could provide a boon. Especially if one player chatted the coded message to his ally over open air. Of course this would only work if the other team didn't know this software existed. : ) very cool idea. I can't wait to give it a shot.
Matt Lowe <> - Sat Jul 2 00:43:27 CEST 2005
A great simulator, down to minute detail!
Thabo < not@guestbook> - Mon Jun 20 17:19:50 CEST 2005
habe mich sehr über die ENIGMA Simulation gefreut.
Diese ist sehr gut programmiert und das beste was ich bis jetzt zu diesem Thema gesehen und ausprobiert habe.
Nur schade, daß dieses Tool nicht in SH3 integriert werden kann!
Es verbleibt mit freundlichen Grüßen
Peter <> - Wed Jun 15 11:33:25 CEST 2005
Dirk, thank you, sir! You've created a real time machine there. Enjoyed decoding those actual messages. Beautiful execution.
Charley Hardman <> - Fri May 27 04:39:25 CEST 2005
Fantastic simulator! amazing detail and functionality. I have been looking for something this good for years, thank you.
Mark <> - Tue May 24 13:23:47 CEST 2005
Erg mooie site met veel waardevolle info.
Heb me altijd geintereseerd voor de U-boot oorlog en dan is een site als dit een must.
Rob Kalverboer <> - Sat May 14 21:03:38 CEST 2005
Thanks a lot for providing the world with this fine piece of software.
It really helps to demonstrate working with this historical machine.
Real eye candy by the way.
Bernd < sorry@not:in.guestbooks> - Sat May 14 15:14:01 CEST 2005
Excellent simulator! Feels like the real thing.
Tim <> - Fri May 13 20:56:53 CEST 2005
A great simulator, down to minute detail!
J. Blake <> - Wed Apr 27 01:10:27 CEST 2005

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