← U-534 messages
← Enigma M4
Message from Dönitz - 1 May 1945
The following message was sent by Grand Admiral Dönitz on 1 May 1945
at 06:55, announcing his appointment as Hitler's successor.
Hitler was already dead at this point. He committed suicide a day earlier,
on 30 April at about 15:30. Dönitz was officially informed about this
by Reichsleiter Bormann on 30 April at 18:35.
Please note that this message was sent before Hitler's death
was officially announced on 1 May 1945 at 22:30.
Broken again by Michael Hörenberg (see below).
The image on the right show the message form as it was found aboard
the sunken U-boat U534.
Although this sheet has been at the bottom of the
sea for more than 40 years, most of it is still readable. Nevertheless,
decoding each individual Enigma operator's handwriting can be a real
challenge by itself, as you can see here.
Below are the settings of the
Enigma machine, followed by the ciphertext
and the plaintext. Note that the first two groups of the ciphertext
are the message indicator. They should be ignored as they are
not part of the text.
One special feature of this message can be spotted immediately.
The settings below reveal that reflector C was used in combination
with Zusatzwalze (Greek wheel) Beta rather than Gamma.
Although Enigma messages were commonly written down in groups of 5 letters,
the Navy used 4-letter groups. They were written down on special message
Although the message forms were rather large, there often wasn't enough
room for the entire text, which is why the Enigma operators used every
free spot on the form for a 4-letter group, even columns that were intended
for something else. With the current message, the last two 4-letter groups
are at the top of the bottom left column under the heading 'Abgegeben An'.
This is a repeat of the message indicator that is also in the first
two 4-letter groups of the message.
Reading a German plaintext message after it has been decoded is not easy.
There are no spaces and some infrequently used letters are used as
punctuation marks. Furthermore, many abbreviations and military expressions
are used. Please note that the text contains errors which can be the result of
typing errors, writing error and errors in sending and receiving
Dan Girard has written a great article about
reconstructing the message below .
- Enigma: M4
- Umkehrwalze (reflector): C
- Zusatzwalze (Greek wheel): Beta
- Walzenlage (wheel order): 568
- Ringstellung (ring setting): EPEL
- Grundstellung (start position): NAEM
- Steckern (plugs): AE BF CM DQ HU JN LX PR SZ VW
- Message key: ??? (see below)
The first two 4-letter groups of the message are the message indicator.
To ensure good reception, the message indicator is repeated at the end
of the message. These message indicators are not part of the actual message and
should therefore be omitted from the ciphertext below.
The message indicator is:
Through a complex process of lookup tables , this produces the
Entering QEOB at the basic setting (Grundstellung) NEAM, reveals the message key:
The Enigma wheels are now set to CDSZ in order to decode the rest of the message.
DUHF TETO LANO TCTO UARB BFPM HPHG CZXT DYGA HGUF XGEW KBLK GJWL QXXT
GPJJ AVTO CKZF SLPP QIHZ FXOE BWII EKFZ LCLO AQJU LJOY HSSM BBGW HZAN
VOII PYRB RTDJ QDJJ OQKC XWDN BBTY VXLY TAPG VEAT XSON PNYN QFUD BBHH
VWEP YEYD OHNL XKZD NWRH DUWU JUMW WVII WZXI VIUQ DRHY MNCY EFUA PNHO
TKHK GDNP SAKN UAGH JZSM JBMH VTRE QEDG XHLZ WIFU SKDQ VELN MIMI THBH
DBWV HDFY HJOQ IHOR TDJD BWXE MEAY XGYQ XOHF DMYU XXNO JAZR SGHP LWML
RECW WUTL RTTV LBHY OORG LGOW UXNX HMHY FAAC QEKT HSJW DUHF TETO
KRKR ALLE XX
FOLGENDES IST SOFORT BEKANNTZUGEBEN XX
ICH HABE FOLGELNBE BEFEHL ERHALTEN XX
J ANSTERLE DES BISHERIGXN REICHSMARSCHALLS J GOERING J SETZT DER
FUEHRER SIE Y HVRR GRZSSADMIRAL Y
ALS SEINEN NACHFOLGER EIN X SCHRIFTLSCHE VOLLMACHT UNTERWEGS X
ABSOFORT SOLLEN SIE SAEMTLICHE MASSNAHMEN VERFUEGEN Y DIE SICH
AUS DER GEGENWAERTIGEN LAGE ERGEBEN X
GEZ X REICHSLEITEI KK TULPE KK J BORMANN J
OB.D.MMM DURNH FKST.KOM.ADM.UUU BOOIE.KP
KRIEGSNOTMELDUNG [An] Alle:
Folgendes ist sofort bekanntzugeben:
Ich habe folgende Befehl erhalten:
'Anstelle des bisherigen Reichsmarschalls 'Göring' setzt der Führer
Sie, Herr Großadmiral, als seinen Nachfolger ein.
Schriftlische Vollmacht unterwegs.
Ab sofort sollen Sie sämtliche Maßnahmen verfügen,
die sich aus die gegenwärtigen Lage ergeben.
Gez. Reichsleiter (Tulpe) 'Bormann'
[Von] Oberbefehlshaber der Marine,
durch Funkstelle der Kommandierender Admiral der Unterseeboote.
WAR EMERGENCY MESSAGE [To] All:
The following is to be announced immediately:
I have received the following order: 'In place of former
Reichsmarschall 'Göring', the Führer has appointed you,
Herr Grossadmiral, as his successor.
Written authorization [is] on the way.
Effective immediately, you are to order all measures
that are required by the present situation.
Signed, Reichsleiter (Tulpe) 'Bormann':
[From] Commander-in-Chief of the Navy,
[sent] by way of the Radio Station
of the Commanding Admiral of Submarines
The message shown here was recovered from the German submarine
U-534 that was sunk on 5 May 1945.
In 1993 the ship was recovered and some Enigma messages were found intact.
In 2012, Michael Hörenberg set out to break the recovered messages by means
of distributed computing power, using a modified software Turing Bombe
and ciphertext-only attacks.
The image on the right shows part of the original message
sheet as it was recovered from the U-534.
It was broken by Michael Hörenberg on 20 October 2012.
You may download the original message sheets1 by using
➤ Original message
➤ Alternative copy
The first one is a message on an original sheet
(Schlüsselzettel), whilst the second one is a copy that was written
at the back of another form. It was probably taken at a later time or date.
Reconstructing the ciphertext of the message above was not an
easy task. Both copies of the ciphertext contain a series of mistakes
that were probably caused by bad reception of the
e.g. where an 'L' (•–••) was mistaken
for an 'R' (•–•). Furthermore, the exact sequence
of the 4-letter groups on the original form (Schlüsselzettel)
was not entirely clear, whilst on the second copy one 4-letter
group was missing completely.
Dan Girard has written a
in which he describes
the difficulties he encountered when reconstructing the Dönitz Message .
➤ More about the U-534
Enigma M4 messages reproduced here by kind permission from
Michael Hörenberg .
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© Crypto Museum. Created: Sunday 03 May 2015. Last changed: Friday, 23 February 2018 - 22:28 CET.