I'm really worried about my friend Friedrich, until today I haven't heard anything from him for the last few weeks. I decided to message him and ask if anything is wrong, and he responded with some weird messages. Now I'm even more concerned! I screenshotted the messages for you to see (I also included a text-only version).

a completely irrelevant image description

Me on Fri, 09/09/2016 18:15:
I noticed you haven't been online for a few weeks. Is everything OK?

I/MFree on Fri, 09/09/2016 18:18:

Me on Fri, 09/09/2016 18:24:
What the hell are you saying? What happened?

I/MFree on Fri, 09/09/2016 18:27:

Me on Fri, 09/09/2016 18:32:
You're really freaking me out now... Please just answer normally! Where are you?

I/MFree on Fri, 09/09/2016 18:39:

Some additional clarifications/info:

  • The dates are in the format dd/mm/yyyy.
  • The time is in the format hh:mm.
  • He, for some reason, changed his username to I/MFree.
  • I'll update if anything worth mentioning happens, assuming someone didn't solve it by then.

Update #1

He just sent me a new message! It seems to be independent from the others, since he only responded when I sent something before. Maybe it's not even encrypted!

I/MFree on Sat, 10/09/2016 10:12:

Update #2

I just sent him a message on Sat, 10/09/2016 20:37, but he never responded back... Weird... Before he always responded to every message! And considering where he comes from, he shouldn't be asleep so early!

Update #3

What does the fact that he is not named "Frederick" but "Friedrich" most likely say about him?

Update #4 (two seperate hints)

The spaces in the message of Update #1 may be more important seperators than you think.

Enigma models

What is he trying to say, what happened to him and where is he?

  • $\begingroup$ (1) Can you clarify what you're saying about I/MFree? (E.g., did you learn it through some other communication, which you aren't showing us? Was it in the metadata of the conversation, but you omitted it from the transcript for (un)clarity purposes?)  (2) Are you using the [visual] tag just because you include a decorative image in your question, or do we need to look at the image to solve the puzzle? $\endgroup$ Commented Sep 9, 2016 at 17:47
  • $\begingroup$ @PeregrineRook (1) It's a private 2-user-room, so that's why it's not shown directly inside the message. I learned it because the description of each room always lists the participants, i.e. my username and I/MFree (2) I'm using it only for decoration, since the tag-description doesn't specify it is necessary to look at the image: "A puzzle that incorporates a visual component like pictures, diagrams, drawings, etc. Do not use this tag for puzzles that discuss geometric objects without displaying them. " $\endgroup$
    – user14478
    Commented Sep 9, 2016 at 17:56
  • $\begingroup$ @ArkaKarmakar He hates to eat bacon. I also don't think he likes to troll people with red pentagonal herrings, since the last group of letters in each message is never five characters long (which isn't the case in the baconian), and the Baconian cipher is surely not the only cipher that groups it's letters in five. $\endgroup$
    – user14478
    Commented Sep 10, 2016 at 8:25
  • $\begingroup$ @LukasRotter: Yeah, so your friend thinks (and keeps) about the perfect space everytime and never misuses it ? $\endgroup$
    – user27395
    Commented Sep 10, 2016 at 8:26
  • $\begingroup$ @ArkaKarmakar Not sure what you mean by "perfect space". The spaces are surely not the one's in the plaintext. But yes, he splits the cipher message into groups of 5 correctly. $\endgroup$
    – user14478
    Commented Sep 10, 2016 at 8:30

2 Answers 2


Piggybacking off of everyone else, the solution is to use

An Enigma Machine, where the timestamps on our messages determine the settings of the machine as follows:

Grundstellung: The letters in the three-letter day abbreviation
Ringstellung: In order, the day, month, and last two digits of year
Umkehrwalze (reflector): Presumably determined by the tens digit in the hour - but this is 1 in all cases and we can just use reflector A
Walzenlage: In order, the ones digit of the hour, the tens digit of the minutes, and the ones digit of the minutes

As an example, our first message

has timestamp Fri, 09/09/2016 18:15 indicating the settings
Reflector A, with wheels VIII I V initially set to 9-9-16 and the display initially set to F-R-I

In order, Friedrich's messages decode to:


the last of which are coordinates to Friedrich


  • $\begingroup$ This is exactly the method I used (as described in my answer), but when I try to put the cipher text into a decoder, it still comes out as gibberish. I used exactly the same keys as you on the first message using the decoder here, and it came out to TISBE BZDPP TOP. How did you manage to get the right plaintext?!?! $\endgroup$ Commented Sep 17, 2016 at 12:57
  • $\begingroup$ @randal'thor That machine doesn't have reflector A, since it dropped out of use before the M3 came into use. I used Py-Enigma and I had to manually code in reflector A, but the machine Lukas linked to does have reflector A. $\endgroup$
    – Will
    Commented Sep 17, 2016 at 12:59
  • $\begingroup$ I just tried with that link and got the 'plaintext' HGYXV UQXJK QYL when using reflector A. $\endgroup$ Commented Sep 17, 2016 at 13:01
  • $\begingroup$ @randal'thor The text in the red box at the top should read Walzen: A. VIII I V (F,R,I) Ringstellung: 09 09 16 Stecker: - - to decode the first message. $\endgroup$
    – Will
    Commented Sep 17, 2016 at 13:05
  • $\begingroup$ Ah, got it now. I'd accidentally put 20 instead of 16. Still, none of the online resources I'd found had an A reflector wheel. I don't know how Lukas found that one. If only I'd logged in a couple of hours earlier this morning, I would've solved it :-/ $\endgroup$ Commented Sep 17, 2016 at 13:10

With the help of Update #3, I've worked out the encryption method:

Friedrich's name is German, so we should be thinking of the Enigma machine. (Originally I'd assumed the OP simply used the sort of name he's used to - according to his profile, he lives in Austria. But apparently this Germanness of name was meant as a clue.)

Now I don't know much about this encryption method, and haven't been able to find much helpful material online either, but with the aid of this site I'm slowly beginning to unravel it.

The settings for the machine (not including the ciphertext) are supposed to look like this:

where (1) is a single-letter "umkehrwalze"/reflector wheel (B or C), (2) is a three-number "walzenlage"/wheel order (in this case, 241) to tell us the order of some wheels, (3) is a three-letter "ringstellung"/ring setting, (4) is a three-letter "grundstellung"/start position**, and (5) is a sequence of letter pairs called the "steckerbrett"/plugboard.

So, what's the relevant information from our Friedrich, other than the obvious ciphertext?

  • The username I/MFree.
  • The dates and times of the messages, in the form day, dd/mm/yyyy hh:mm. (According to the OP, we don't have to worry about the timestamps of Friedrich's messages, only of the ones from 'you', the narrator.)

We also have Update #1, which says WP-WP-WP RS-RS-RS R-WO-WO-WO. This looks like (thanks @JoeDerksen who realised this):

WP for Wheel Position (= grundstellung?), RS for Ring Setting (= ringstellung), R for reflector (= umkehrwalze), WO for wheel order (= walzenlage).

Which tells us how to get most of what we need for the key, from the message times in the form day, dd/mm/yyyy hh:mm. Note also the division of both this timestamp and the message in Update #1 into three groups of characters separated by spaces. This suggests the following meaning for the key.

The day of the week gives us the grundstellung; the day, month, and year, translated from numbers to letters, give us the ringstellung; and the hours and minutes give us the umkehrwalze and walzenlage. Thus, for example, Fri, 09/09/2016 18:27 gives grundstellung FRI, ringstellung IIT, umkehrwalze corresponding to 1 (?) and walzenlage 8,2,7.

I'm still not sure about either the meaning of I/MFree (although note that the division of these six letters into one and five is important, according to the OP) or

how to decide the steckerbrett,

but I'm definitely getting closer!

[work in progress]

  • $\begingroup$ Nice. But the / in I/MFree is actually relevant, and the username isn't used for the wheel positions / ring settings. It's allowed to have repeated letters in the wheel positions. Update #1 is supposed to help you which parts to map to which components/keys of the enigma machine. $\endgroup$
    – user14478
    Commented Sep 14, 2016 at 7:30
  • $\begingroup$ Not sure if this will help, update #1 says " WP-WP-WP RS-RS-RS R-WO-WO-WO " , maybe RS means Ring Setting (number 3 in your picture), R means Reflector or Umkehrwalze(1) and WO means wheel order, walzenlage (2). I would guess that WP is the number (4). Wheel Position. So we're looking for a sequence of 6 letters followed by either B or C, followed by 3 numbers. Still have no clues for the steckerbrett though $\endgroup$ Commented Sep 14, 2016 at 15:20
  • $\begingroup$ Wasn't the Steckerbrett a later addition? (OK, I looked it up. Added in 1930.) Perhaps it isn't used here. $\endgroup$
    – Gareth McCaughan
    Commented Sep 14, 2016 at 23:12
  • $\begingroup$ Update #2 seems to indicate that some dates-and-times are no good, which ought to convey some more information about exactly what bits indicate what settings. $\endgroup$
    – Gareth McCaughan
    Commented Sep 14, 2016 at 23:15
  • $\begingroup$ @Gareth Yeah, I'm not 100% certain about my way of getting the grundstellung and ringstellung. The mod-26 bit in particular has me a bit doubtful, but I can't see any other way to do it except perhaps taking the minutes part of the timestamp digit by digit. $\endgroup$ Commented Sep 14, 2016 at 23:17

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