CIPHER MACHINES AND CRYPTOLOGY Enigma Cipher Challenge Home Menu Table Of Honor Procedures Enigma Simulator

The challenge Working with the Enigma cipher machine is not that hard. At least, if you have the secret machine settings! What if you were a codebreaker at Bletchley Park? What if the lives of many people depended on your skills? Do you have it in you, to break the code? Well, this is your moment of glory... The Enigma cipher challenge gives you the chance to show your code breaking skills. Anyone who is interested in the Enigma machine can join the challenge. You don't need to be a professional cryptologist or math geek! There are ten messages or stages, each one a bit more difficult to solve than the previous. You can use the Enigma simulator (see image) or any other correct working Enigma software to decipher the messages. You'll need a bit of logical thinking, some patience and a bit of luck. Of course, you will have translate the German language message, or did you believe the Germans wrote their messages in English? Don't panic! You don't need to know German or be a polyglot. You can read these translation tips and find all you need to translate the messages, and/or use an on-line translator. For more info on how to use the Enigma machine, please read the procedures page .

*** LATEST NEWS *** Valentin-Daniel Popa from Romania is the 65th participant to decrypted all messages on September 27, 2020. Congratulations Vali!

You can still participate in the Challenge! Your codebreaking results will be listed below in the All-time Table Of Honor

304 codebreakers from 38 different countries have already joined the challenge. You can join them! Your task It's your task as codebreaker to decipher and translate the messages. I don't ask for a perfect English translation, but the content must be clear and usable to our SIGINT Officer. Here are some translation tips. Of course, I cannot accept errors on important parts such as grid numbers, names of places etc. The stages have to be solved one by one. I tried to capture the most important moments of the war in the ten messages. You might find help or clues in your WW2 history books or on the internet. Googling around on names of operations, people, units or boats that appear in the messages will bring you some amazing wartime stories! Important note : to simplify the key identification, the challenge procedure does not use Kenngruppen in the message. How to participate If you have solved a message, it's important to mail me without hesitation your name, the stage and the translation in English. Your position in the table is relative to the number of solved stages and the time you needed for each stage. Therefore, if you have solved one stage, mail me the solution first, before proceeding to the next stage. If you didn't solve a given stage, you won't get credits for the next stage! It is not allowed to publish or distribute the copyrighted deciphered challenge messages electronically, in print, or in any other form, on the Internet or anywhere else, in order to preserve the value of any future challenge table results. Finally, what can you win? The respect of your fellow codebreakers, the gratitude of our boys in the frontline, and a place in the Table Of Honor! ACTION NOW ! 1

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Table of Honor



Message 1 May 10, 1941 Sir, we have received a message from our Y-station in Scarborough. They intercepted this U-boat message in the North Atlantic. Harry Hinsley tipped us off that those weather ships probably use the same code books as the U-boats. Well, last week, we had a stroke of luck. Our Navy boys captured some papers on a German weather ship, the Munchen. Here's the sheet we found on the Munchen. Seems the Officer made it a bit easier for the radio operator on the night shift. Let's hope they keep making these security mistakes! This should be an easy one. The message, intercepted by our Y-station on May 6: U35 DE W7 0630 = 46 = WTG PLT = MUUQ JZVQ LORV MCOL YKXE PMCD CWGH NTQV MEHG ECOE ULBU LBOC ZPGB IXIF WCYX ZKZK LYAE VCJD GXJZ QKQG VXSO RRQN ZMAT PZDO EXIT XFIU VJFI ZUAY LIJW VVGF YXGR DQKA GUUW BNUU OUXQ QUCX KUXP TYUI IXPA YXRL TZPZ QRNL OPAO DDUS VFWM ILZE OBVO PIPW HXVY ADCO RXPI IEUZ VTXB RJRE CTGL CPKQ AJDA MI I hope the captured papers can help you, Sir. Good luck! Message 2 June 20, 1941 We have good news from the SOE team in Norway. They managed to infiltrate in the German Mountaineer Corps. Apparently, they are preparing for something big. The SOE team has located an Enigma machine over there. We have received a message through the Norwegian resistance. We now have the plugboard settings and the wheels used. Unfortunately, all wheels were extracted from the machine. We have one big clue: Three of them are not zeroised, so these might be the used wheels for today. If we can find out the wheel order, we may have a chance on the intercepted message. The message from our SOE agent: FM SPECIAL OPERATIONS EXECUTIVE NORWAY TO SPEC LIASON OFFR BP O 201145B JUN 41 MSG 005/32 RECOVERED ENIGMA SETTINGS JUN 20 THE NON ZEROISED WHEELS IN THE BOX ARE I(7) III(25) V(3) WHEEL ORDER UNKNOWN B REFLECTOR STILL IN MACHINE CONNECTED PLUGS BL CK DG FP IR MO QW ST VY UZ The message, in two parts, picked up in Kirkenes, Norway: ABSENDESTELLE : LII ARMEE KORPS KDR AN 2GD KDR FUER 2GB 1840 - 2TL 1TL 182 - XLT VPM - RGOXT IVDHR FWGIK PUKXK CTISB GRIKM MYAAA SMQFH ZGLBU ZGOFG MGOJF BOPYU KMPPX VGIBT FYGKO LISPX CLRRE QXOUQ OMXIJ OKWYQ NHHQX SYCOJ QGYDU NTPMI LYDOO BPLFV JQTIZ FHHUW GXACF TTHGI SJHXS RWOPP CCMUA CJFNV VUBGV QFDET VS 2TL 117 - HNB SFA - NGWTV VGTHG ZPQGF EXSWN FKSXH POJCM PGHLL CAJCP UVIQU UZLQW AVOTS CPZFA BNUOR ZZAFM CJPGP TGTDR GWTZA XNQRY JCBMQ ZVCQU CQOCO JGNYN UCAVO MA With the correct wheel order we should be able to break this one, Sir. Message 3 November 25, 1941 Sir, I think we're on to something. Our listening station has intercepted a radio message. According to the direction findings, it's broadcast from somewhere around Kiel in Germany. We believe it comes from the U-boat shipyard. It's a Wehrmacht message. We have already broken the Wehrmacht keys for today, but we still have some problems with the plugboard settings. I believe you're the right person to figure this out. The Wehrmacht keys for today. Unfortunately, we have one plug connection missing: Wehrmacht setting for November 25, 1941 Rotors : III - II - V Rings : 8 - 19 - 3 Reflector: C Plugs : AL FP HX JO KT NV QR SU WY Here's the message from Kiel: UBB DE GWK 1520 = 57 = AST SGT = ZJTPL TJNET NLLGO PQVSW XSRHC OSHUT FGUSH HTVPO UMBMV GKLAA FDUBN UVCUV POCFJ XDMIQ CCAUC BQOKP HUMCI ZAJVI QESVG CFHDT ISREH FCMBP JCRTW TTMXC NOIEU WRPOM CEMSU NBBCT WZZRB LFLUF IFBNY OYJGX UMNKP TCQHT GVYWS QDFFM SWVEC IDWIL ZBYLI PRXYI CFCLP DQZNO ZWSKV NJURT GKMWU NFPNL EPOFQ LJMED EFNML RRRRJ YTBVR KBQQG SUWVA WAFUU WFLMP KPHLD ML Let's hope we can figure out the plug settings. We'll just have to see which letters in the message are wrong. Always good to have an insight on that U-boat yard. Message 4 December 15, 1941 We have an incomplete message, on which we have worked out the first two wheels with our Bombes. Hut Six has done a great job on the plugboard. Your job is to find the position of the leftmost wheel. According to the SIGINT Officer, traffic analysis has shown that the message probably was sent from St-Nazair to Lorient. Admiral Donitz is visiting the St-Nazair U-boat harbor at this very moment, so this might be interesting. Here's all we got from Hut Six, together with the partial St-Nazair message: ... KGBJN TWBQY FFJWQ KKCTN ZJVRK BWPQO FZQTB LCYCM WCWTR XSGKA WIZEZ KFIWC KPEYB OBUBW VUHBO BKEGF WGGSQ WUMIO BKHSF TXAGY XPKAX AOJQJ ANZKZ REKYX TXWWR HJHST EJAJS QFZMZ FLTSE QXBAZ WDSJR WHVGF KIXLM PUYIN NQSAW QHXAJ QJCGU CQUFI HWAFN AAFPR ZSMTR KYLUG AOZKY NMXFC HQQEV MTTIN CHTSW CYCRZ FBKMB VSHEK XDYCY PWSZJ WVZAK IRMSQ DZKTF DDEUX WKXMN PDMKD RKASA ORATL JAEHW INMVR SWASF ...

Message 5 December 9, 1942 Sir, our SOE has received a message from the NKVD, the Russian secret service. NKVD has intercepted a message near Stalingrad, where the VI Army Corps of General Paulus is surrounded by Soviet forces. They are asking our help in breaking the intercepted message. This might be crucial information to turn the tide in Stalingrad. The Wehrmacht settings for today. We didn't have the message key, so we ran the message through our Bombes. As you can see, we failed to resolve the rightmost wheel. Since it's a Wehrmacht Enigma, we can only choose between wheel I, III and V. We're also missing the ring settings to that wheel. An error on the rings can result in unreadable text after an initial good start, due to a wrong turnover point. If so, the ring should then be adjusted. I believe the message comes from the Oberkommando Der Wehrmacht (OKW), so I'm guessing, well, and educated guess, that the message could begin with "VON OKW" or "VON JOKWJ". If this is correct, we have a great crib to find the rest of the message. Rotors : II - IV - ? Rings : 9 - 2 - ? Reflector : B Startposition: E - F - ? Plugs : AS CK DE FV GJ LU MW OT PX RZ The message, intercepted by NKVD: ... ACINZ CRVFJ RPETN UGAVD ZIHXF WTPKK TTVXZ JTAYN XRQMA JKKFI WUXTN HFCMZ PUUYP PKILQ YBYRD MHFBM HPGYL CEIJU NMWGQ OKGHM DLGJW BQBZB VWDTS UWHGX ZRFUX WQTHT RHYPT PJZRO FTCNM XCKSD DNHIW YSUGQ RZUIY IUOTD ZPQRT CXVQX PMZGJ BWLHX ULWLU NLWPW NTONB QUFMM IKNTV WNK ... Could this help the Soviets beat the Nazi's? Message 6 February 19, 1943 Sir, we received an urgent message from our Special Liaisons Unit in Tripoli. You know that Montgomery's 8th Army took Tripoli last month. Rommel's DAK, the Deutsche Afrikakorps, has now been cut off from its main supply. This could be a turning point. Therefore, the deciphering of all DAK messages has priority. Our colleagues have set all their efforts on breaking the German and Italian codes for Africa, and with success! We got into the DAK message traffic. This is the note on the African keys, from Hut 3: However, we also have some bad news. Our Y-station, attached to Monty's HQ, had a really bad radio reception. The result is quite disturbing. We lost some pieces of text, and worse, we lost some parts of the message keys. Maybe a Herivel Tip could be useful? But that's were you can earn your stripes, Sir! We've marked all missing pieces with an equal sign. Don't forget to skip then, while deciphering! ABSENDE STELLE : 21PZD AN OKW FUER WSTF 1840 - 3TL 1TL 250 - ACE =WE - OLDTO GVQQY DCOZN NVUMD FJIOC JV=AZ MZJRE GOBDI VNYRF TUAZS RUDPO HWZRL LKHMC CJUKR YRJMR TXMGA UJMKG IENYA ZKXSS OTGWO DHUQP YILYG CSJHV QNILS ITWQY XBFNA GTSWM XJTSM OTVMG HVDZB SQBDL SH==E ZUHMP GGGMX HIJFY IHWBJ WJAKO TCOKO VCPNR QJPKN IRPYP TFWPB MUPHO HPIBR KRQNA OYHHS BYPBB XPKAF =JIFX GOUPZ 2TL 250 - SED A== - DQHFX QVZSX RJJYJ KKGWU Q==IU LIXBO EMFQX AALQX CUYKO KPPVV SGVBG RUAER DDOFA OWCGP PCUSW IQQKK EHGXO CVYFQ TZICT JKOOF QQJLH DXMDX TKCTC IMI=H YKJQQ IDEGK RAXQT UELIS PWGJC OGHES ZBILO UISLS OKVIO LHZSR HEXUJ AYITW DQNKO HVERX WNMJZ TBSBP SMMCM TG=== UIZKN VDWDD VEHHN EUPCN GJDLN DOZXS VZBYD UPCTI 3TL 112 - HIP PYX - DQC== =THQP LAEIS ZHDJE OFQVA AXXWN GUTIM MXSNA ORBRO WKDTH MOCUI MZJNZ SWTLU OYCAQ XAKGD AMVWS GFYMF PFJXH GCHAS LLHIM OMSZE ZBRLL JM And Sir, it's urgent, could you get this finished by yesterday? Message 7 May 15, 1944 MI5 has requested to keep them informed on the results of Operation Fortitude, the deceptions for D-day, to check if the Double Cross system pays off. Operation Quicksilver, with its fictitious 1st U.S. Army group, is a key element of Fortitude South. SIGINT has reported a rise in some French message traffic. According to their direction findings, it's probably from the German Army Group West. Curious what they have to say... Sir, this is what we're facing: The key for today is still unbroken, but last week, a Special Operations Executive team in France recovered a Wehrmacht code sheet, that should have been destroyed by the operator. Well, you would be surprised what you can find in a dirt barge. You should be able to deduce the plugs and rings for May 15, knowing the structure of a code sheet. Too bad we don't know which of the five Wehrmacht rotors or reflector were used. Click the image to enlarge. Here's the message, Sir. Enjoy the night shift! FUER OBF 1300 - 2TL 1TL 250 - AEG GJW - MLETW NNJZJ ECTHJ JUUVD DBAZS XBVOF SEWLR MLSBX GNLNL LLIGO IMYMU HBGRI HZTFG TXKCT CRPJN BHZMQ QWGUA KBJXJ BITQI BFXMZ MHHWK OBSSD OGELQ UWQXG IMLVG YJQSL PIQNZ VQVFN LGQXN PUJEZ MPUNC MLETS JIXZP HUNBN AGVCB SAAIN IIHJV CWISA NHEMW JOEIY MXSFE JAEPU FJLIT VUZYS HYWYP XTAYJ CARWI YORFI VANOM BXWDT 2TL 187 - VSF DNA - EWGYY LDFBK IBHZA CZZZP ABUCX BLLZF KPVAX ZDJXJ GGZZQ RWURS LFLBV KAQTJ PMUXH NIPUC IWSFY ROEIQ QHNFO TPVAF RFNLQ OAXRE GZPJR WYYIL BGZSP PBVTL BRIGO QXION BZSZX ANZES UJTEN ZVWRS VRJPP OZLWV IMCKO YQFWY FTCPT ZSERJ DBPTA UUJGM Message 8 December 12, 1944 The 1st Canadian Army has finally cleared the Westerschelde, opening the ports of Antwerp to our supply ships. Although the supply situation is a little better, all Allied forces are now spread all over France, Belgium and Luxemburg. This could weaken our troops, while German forces are drawing back behind their borders, concentrating their troops and supplies. They also switched more and more from radio to telephone network to communicate. This mean less intercepts and less ULTRA information for Special Liaison Units. Each intercepted message can make the difference. At 0900 hrs, U.S. 2nd Division has found an Enigma machine in a German Signals Truck near Sankt-Vith in Belgium, destroyed by our airplanes. The machine was still on key, but its plugboard was badly damaged, and missing some plugs. This is all we got from them: This is one of the few messages, intercepted today. ABSENDE STELLE : AG/W AN AG/B FUER BFB 1300 - 3TL 1TL 250 - BKL UPR - SIAZK QGEML IVDBI YWAKC AMPYK CFLOP QDCWP VMITC WAYWK BRUJA VGRYY CISIJ ZSGRM TZEKG EQLWU XIXYP MQLUH ODQFP NRKBZ DISWX PHYDB NEQHJ UZJRZ FWWMV TGIXF SFCQI BVMHG ENWKN KYXMQ RYSMA WCMBW FHYPN WJEBV YBZEZ RCUFZ YLIFF JCQFK GOGBY GXMDJ LUJMM KZDLN NNJIY EAOYU VDFRF CCUVP WYPJH WFSGG RLXQD FFOKL SKGXZ 2TL 250 - SPL BKK - YNDXI HNTJY ETDDJ VBPCA PORBP PASUK HYHTH ETMFG JNPUF WAMEB FIKQB ZGGFZ ZXJMU YNJDW XJXZD MEEVP YRDGP YMAXW TWHUG DQZTM JWKYQ RDQXK VGTZY IIMPB VDJPQ VJLOI OSXQE NZZHC NTWCQ YQYMH COXPN TDXMT ZWABT WRVYI GMJEI CMHXH HEITF PKXEF WMICO VTIVI BIEAC PFVXZ ILJXW TBRVB EFENE WQZTC CDMWV WGLDZ TXGUD JWSTR 3TL 137 - DVB LTK - BKWVQ ICHPW RRYJD AXQEI QJKQQ YMLTP VAKYC JZZTD AODOL STOKL SSXJR TQCKI KGRRD RJZYZ WWJPT ABZJE OWGRU KLASP PBMKZ BJRHI OKPAK YFZPC OUAAX DMZQM TLDFN NKEZD GRNUZ QA Message 9 December 28, 1944 I think we're on a turning point, Sir. The U.S. 7th Army has reached the Vosges Mountains. If they can go on like this, the German troops will soon collapse. As they are drawing back, German troops leave all kinds of equipment behind. They seem to be in a hurry. They didn't even had time to destroy their secret documents. We have put our hands on a Wehrmacht code sheet, containing today's key settings. The key settings, delivered on a silver plate, with many thanks to the fleeing German elite troops. General Patton would appreciate all information, useful to his 7th and 3rd Army. If you break this partial message, this could be a nice Christmas present for the battered troops, stuck in the snow and cold. ... INAVH YMVHI AGMJO PKVJH SGJYY KNHLF KRZWH WLAKK EGGHZ FEAKV VIDDS YYVEY QFQJP VYHLF UZESA OLGNH TXTTB DZJVO AGEAW HBBWC ADYYT HSLRX MPEDI CATSM ALBZY LBPZM QDSXZ HPFSX VYCBK GEBTG QGZII DQJDB YDACS WJGXU CUXLT RTMZH HWXZP ESSYE EPFCQ AOWOS PLUZU CVOKY JXCPY GNJHS PNCFS WTLLM SGACQ BSUTP SAVGU YFVKS UBSQE GVZKV NRLXF IXZQW FKSXC PPFRI MWQHT QSB... Message 10 April 29, 1945 Well, Sir, I think we won't have to spend our summer vacation in Bletchley Park. U.S. troops are at the gates of Berlin. The Soviet army is already engaged in heavy fighting in the Berlin streets. I wonder what our friend Adolf is doing at this very moment. He's probably doing it in his pants, in the Reichskanzelei Bunker. But work isn't finished. SIGINT still intercepted some messages from Berlin. I have a message for you, a long message, and they even didn't bother to divide it into parts. They must be desperate, those Germans. Well, so much easier for our statistics guys. I wonder why, and to whom, they still want to send these long messages. Very strange. I'm curious as to what they are doing over there. This is probably one of the last messages send on an Enigma machine in this War. One last effort, Sir. No key sheets or setting this time. If you break this one, you're an ace in codebreaking. Good Luck! FUER ODES 2155 - EDF GXT - KYYUG IWKSE YPQDF YPIJN TGNDI AHNBR OXDIK EKPTM OUHBE JRRJP VBAOC UZRDF SAZDC NUNNM RPCCM CHJBW STIKZ IREBB VJQAX ZARIY VANIJ VOLDN BUMXX FNZVR QEGOY XEVVN MPWEB SKEUT JJOKP BKLHI YWGNF FPXKI EWSNT LMDKY IDMOF PTDFJ AZOHV VQETN IPVZG TUMYJ CMSEA KTYEL PZUNH EYFCL AADYP EEXMH QMVAV ZZDOI MGLER BBLAT HQJIY CBSUP VVTRA DCRDD STYIX YFEAF ZYLNZ ZDPNN XXZJN RCWEX MTYRJ OIAOE KNRXG XPNMT DGKFZ DSYHM UJAPO BGANC RCZTM EPXES DZTTJ ZGNGQ RMKNC ZNAFM DAXXT JSRTA ZTZKR TOXHA HTNPE VNAAV UZMHL PXLMS TWELS OBCTM BKGCJ KMDPD QQGCZ HMIOC GRPDJ EZTYV DQGNP UKCGK FFWMN KWPSC LENWH UEYCL YVHZN KNVSC ZXUXD PZBDP SYODL QRLCG HARLF MMTPO CUMOQ LGJJA VXHZZ VBFLX HNNEJ XS