The cache is not at the posted coordinates
For this puzzle we will look at how people used ciphers before computers (and website solvers) right up to mechanically encrypted ciphers using the German Naval Enigma Machine.
Note. Links provided in the cache description are for reference and/or supplementary information purposes only. They are not required reading to solve this mystery cache.
Since the beginning of written language there have always been occasions when someone wishes to send a message to be read by the intended recipient and by no other person. In such situations, the sender and recipient must agree on a method to encrypt and decrypt their communication.
One of the earliest ciphers - well-known to all geocachers - is the Caesar cipher which encrypts the original message by replacing each plaintext letter with a different one a fixed number of places down the alphabet. The result is the ciphertext which is decrypted by reversing the process. Another substitution cipher is the Atbash cipher which replaces plaintext letters with the corresponding letter when the alphabet is written backward, so that A becomes Z, B becomes Y, C becomes X, etc. Again, the message is decrypted by reversing the encryption process.
These simple substitution ciphers offer very little security and the method of their decryption was revealed in a book called "A Manuscript on Deciphering Cryptographic Messages" which was written over a thousand years ago. This book demonstrates that no matter which method of encryption is used, all simple substitution ciphers are vulnerable to an attack model known as frequency analysis. The same holds true even when symbols or pictograms are used in place of letters (eg. the gold bug, dancing men, and pigpen ciphers.)
Unlike a substitution cipher (which changes the characters of the plaintext message), a transposition cipher retains the original characters but shuffles them around in a way that makes it difficult to read by anyone but the recipient who has been apprised of the method required to decrypt the ciphertext. There are many variations of transposition ciphers (eg. ADFGVX and rail fence ciphers) but the basics can be demonstrated most easily by rearranging columns and rows. For example, if we wanted to encrypt the phrase "The quick brown fox jumps over the lazy dog" we would first arrange the letters into a block of text. Like this:
T H E Q U I
C K B R O W
N F O X J U
M P S O V E
R T H E L A
Z Y D O G
Then it is just a matter of reading the letters down each column. This renders: TCNMRZ HKFPTY EBOSHD QRXOEO UOJVLG IWUEA, which, to the casual observer has no meaning, but a recipient could easily reverse the process to obtain the original message.
To make decryption more challenging, people have developed sophisticated ways of rearranging the columns of the above using keys, and some have resorted to double encryption (a process of encrypting a message twice using different keys each time) but when it comes right down to it, transposition ciphers are a complex way to create anagrams which can be solved by anyone with sufficient vocabulary or a dictionary. Short messages offer no security, while longer message may pose challenges but the context of the message will increase vulnerability to decryption.
Both simple substitution and transposition ciphers have many sub-types but each variant is vulnerable to the same process of cryptanalysis as the parent type.
Note. Steganography is a means and channel for concealing delivery. It is not a cipher per se so it has no place in the current topic.
Cryptographers recognized the problems with simple substitution and transposition ciphers and sought improved methods for sending secure communications. A major hurdle was that no alternatives were available. One either changed the order of the letters, or changed the letters themselves. The prospect of combining both methods was deemed impractical since a minor error during encryption or decryption rendered the exercise meaningless and therefore a waste of time. Since transposition only ever creates anagrams, focus swung toward substitution ciphers. So...
In the fifteenth century, a fella by the name of Alberti figured that the best way to thwart frequency analysis was to avoid using a constant shift (aka rotation), when using a Caesar cipher, and instead he changed the amount of rotation several times in the middle of the same message. Thus, using multiple alphabets in a single message. This concept resulted in the very first Dick Tracy decoder ring. The problem was, however, that Alberti had to include signs and markers in the ciphertext to indicate where and when to change the degree of rotation and thereby provided clues to decryption.
In order to correct this shortcoming, a dude called Trithemius created, in 1518, a table containing all shifts of the Caesar cipher type.
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| A | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| B | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A |
| C | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B |
| D | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C |
| E | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D |
| F | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E |
| G | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F |
| H | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G |
| I | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H |
| J | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I |
| K | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J |
| L | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K |
| M | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L |
| N | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M |
| O | O | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N |
| P | P | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O |
| Q | Q | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P |
| R | R | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q |
| S | S | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R |
| T | T | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S |
| U | U | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T |
| V | V | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U |
| W | W | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V |
| X | X | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W |
| Y | Y | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X |
| Z | Z | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y |
He called his table the Tabula recta and proposed progression through a series of shifts for each and every letter. That is, the first letter of plaintext would use the corresponding letter in the first column; the second letter of plaintext would use the corresponding letter in the second column; and so on. When the twenty-seventh letter of plaintext was reached, one would return to the first column and continue. The result would defy frequency analysis but encryption was systematic, methodical and ultimately predicable, and therefore no more secure than its predecessors.
About fifty years later, a scholar by the name of Bellaso introduced the concept of a 'key' to Trithemius' Tabula recta and for all intents and purposes invented the Vigenère cipher which remained uncrackable for the next three-hundred years.
The way the Vigenère cipher works is that instead of using all twenty-six columns sequentially for encryption, the sender uses only the columns indicated by a keyword, which is then repeated for the entire length of the message. For example, if the key is HORSE, then the first letter of plaintext would use the corresponding letter in the 'H' column; the second letter of plaintext would use the corresponding letter in the 'O' column; and so on. When the last letter of the key is reached, the encrypter returns to the first key-letter column and continues in this way until the ciphertext is complete.
Now, one would imagine that using fewer, rather than all, of the columns in the Tabula recta would make the cipher easier to break, but such is not the case because using random keys removes the element of predictability, and if one selects heterograms for keys, then there are no repeated sequences involved and frequency analysis fails. At this level, then, attacking the Vigenère ciphertext is not possible. However! If we change the task from decrypting the cipher to discovering the key we can achieve success. Fortunately, for us, wikipedia provides details about how this may be accomplished, and The Black Chamber offers tools to assist in the process. It is a fascinating topic, so if you are interested then by all means spend some time examining these and other internet resources. For us today, though, it is enough to recognize the complexity of the Vigenère cipher and, perhaps more importantly, to know there are methods available to crack it.
Unbreakable ciphers?
If a sender of a message using the Vigenère cipher uses a unique keyphrase or string of text the same length as the message itself, then that would no longer be a Vigenère cipher but becomes a One-time pad cipher. Such a cipher is the most secure manually encrypted and decrypted cipher ever devised and it is virtually uncrackable. Unfortunately, it is also clunky and impractical, and depends on providing the recipient with a bulky book of unique keys which can only be used once and each key must be destroyed after use. Oh, and the code book must be replaced should a copy of it fall into undesirable hands.
Similarly, if a sender uses a non-standard alphabet (scrambled, shuffled, reversed, etc.) when creating their tabula recta then discovering the plaintext becomes less likely, if not impossible. The trouble with this scheme is that the sender must also find a way to provide the recipient with the key-table, in which case anyone who intercepts the message is also provided with the decrypting table. Not to mention that key discovery is still vulnerable to the same processes of the standard alphabet. This is nearly uncrackable but contains inherent vulnerabilities.
And lastly, if a sender employs multiple levels (double, triple, or more) of encryption using a combination of standard and non-standard and reverse alphabets in a series of tabula rectae with different keys at each step, then we have no trouble imagining the difficulty of cracking such an operation. Unfortunately, the same caveats apply here as to the two variants just mentioned, and, worse, the recipient will have just as difficult a time with decryption as an unauthorized person will have trying to crack it. In short, a tiny error throws off the entire process at which time we have to begin again. Surely, this scheme offers the most security, but the sender and receiver need some kind of sophisticated cipher disc or other device to aid in the encryption and decryption process. And it is here that we turn our attention to the Enigma Machine.
Historical and technical accounts of the enigma machine have been provided amply in books and on the internet so I will restrict the information I present to crucial concepts and its use.
Parts of the Enigma Machine
Keyboard: The same as a typewriter keyboard, used to input plaintext and ciphertext.
Plugboard: A configurable circuit-board that uses plugs and wires, like an old-fashioned telephone switch-board, to provide a layer of simple substitution.
Rotors: Rotors (or wheels) display all letters of the alphabet, and the displayed letter changes with each key-press, and each rotor will change the position of neighboring rotors at varying rates. Most enigma machines use three or four interchangeable rotors, and each machine is equipped with between five and eight rotors to choose from. The machine operator cannot configure individual rotors but they can change the order in which they are installed in the machine as well as their starting positions.
Rings: In terms of the discussion above, each ring may be thought of in terms of a self-contained tabula recta, each with different configurations. A ring is then affixed to a rotor at a specified position to provide a shifting alphabet with every key-press and subsequent turn of the rotors. This ring-rotor mechanism is the heart of the enigma cipher.
Reflector: A non-configurable, hard-wired circuit-board to provide another layer of simple substitution. The reflector also sends the electric signal back for another pass through the rotors.
Lamps: Used to display output of the plaintext or ciphertext that corresponds with a key-press.
Operating the Enigma Machine
During war-time, an enigma operator would set up their machine according to a rigidly prescribed protocol shared between the sender and receiver. This is imperative or the recipient will not be able to decrypt the message. Once the machine is configured, the operator types a letter of the plaintext on the keyboard, and the circuitry of the machine produces a letter illuminated by a lamp, and the operator notes it down. This is repeated for every letter of the plaintext message. When the message is complete, the operator sends the ciphertext to their correspondent who then reverses the process to obtain the plaintext message.
Seems pretty easy, doesn't it? Neither the sender nor receiver need to know the message is being encrypted by at least two simple substitutions and no less than six complex tabula recta (passed through three rotors twice). To this end, the ciphertext is all but unbreakable.... but broken it was.
If we look forward to today's technology, with methods of computer encryption and decryption (eg AES, DES, PGP, etc.), the enigma machine seems primitive in comparison. But imagine what it would have been like for Alan Turing and his staff to manually decrypt all messages at Bletchley Park!
Bletchley Park was headquarters for Allied code-breaking during the Second World War. Operations at Bletchley Park were vital to British intelligence (Huts 3,4,5), developments in cryptanalysis (Huts 6,7,8), SIS and MI6 (Hut 10), Turing's Bombe (Hut 11), the development of Colossus - the world's first programmable digital electronic computer (Block H) - and laid the foundations of the computer sciences. At its peak, there were as many as ten-thousand people working at Bletchley Park but perhaps the biggest breakthrough came from Alan Turing and his work on the German Naval Enigma Machine (Hut 8).
Bletchley Park's legacy acknowledged, I'm going to short-circuit our discussion before I turn you on to the antics that took place there. I have described the two primary types of cipher (substitution and transposition) each of which, I hope I have shown, can be built up to extraordinarily sophisticated and complex heights. But since we, after all, are only geocaching, I feel it would be unfair to subject you to all the difficulties of code-breaking faced by Alan Turning and his staff: namely, a message written in German without clues to keys and configuration. Instead, I will encrypt and you will decrypt a message written in English produced by the enigma machine and through that process you will arrive at the puzzle which will lead you to the final location of the cache container, and, at the same time, hopefully you will gain, if you haven't already, an appreciation for just how remarkable a development the enigma machine was and how brilliant were the minds that found a way to read its messages unaided. So...
The Codebook
The method of encryption is as important as the message itself. To avoid detection during wartimes the Germans provided codebooks to enigma machine operators (senders and receivers) so they could change its configuration every day. One page in the code book would prescribe setups for an entire month, and would look something like this:
| SECRET! | GCA6BRM | JUNE |
|
| | | Day | | | Rotors | | | Rings | | | Plug connections | | | Daily keys | | |
|
| | | 01 | | | V | II | IV | | | 23 | 03 | 14 | | | AH | CZ | DL | EO | FS | GW | NT | PU | QR | VX | | | GNB | AIF | MJP | QRT | | |
| | | 02 | | | VI | VIII | VII | | | 26 | 23 | 11 | | | AS | BQ | CU | DW | EK | FZ | GO | HL | IR | NX | | | SJG | GPZ | RKD | PDZ | | |
| | | 03 | | | VIII | IV | III | | | 20 | 22 | 13 | | | AQ | BJ | DI | FK | GZ | HR | OS | TX | UY | VW | | | JIL | YCD | DYG | OOT | | |
| | | 04 | | | VI | IV | V | | | 10 | 26 | 06 | | | AP | BM | DR | EZ | FH | GQ | JS | LT | NV | XY | | | DQM | TKJ | BWP | DUY | | |
| | | 05 | | | II | VIII | III | | | 19 | 13 | 12 | | | AY | BP | CQ | DI | EW | FR | GJ | MV | NO | SX | | | OTH | VNF | BIV | KUQ | | |
| | | 06 | | | IV | I | V | | | 20 | 19 | 15 | | | DN | EI | FK | GX | HU | MP | OT | QR | VW | YZ | | | UET | JPU | WOQ | CDK | | |
| | | 07 | | | II | VIII | I | | | 03 | 11 | 13 | | | AR | BP | EY | FO | GK | HN | IX | JT | LV | MZ | | | VJT | RYV | AZW | RSP | | |
| | | 08 | | | IV | V | III | | | 15 | 06 | 23 | | | AJ | BT | DP | EO | HL | KW | NR | QU | SX | YZ | | | CZX | REB | ESR | TQV | | |
| | | 09 | | | VII | IV | VI | | | 01 | 15 | 19 | | | CI | DN | FY | GH | JV | KW | LO | MP | RZ | SX | | | PJU | LEO | QRH | FXL | | |
| | | 10 | | | VII | VIII | III | | | 14 | 24 | 06 | | | AT | BI | CG | DM | EO | HJ | NW | QY | SX | UZ | | | WNX | ZQY | LDF | KZD | | |
| | | 11 | | | VIII | IV | II | | | 20 | 13 | 02 | | | AV | BP | CU | DO | HK | JN | LR | MS | TW | XY | | | KYQ | NHH | WJH | TNS | | |
| | | 12 | | | IV | VII | III | | | 10 | 10 | 13 | | | AQ | BC | DW | ER | FX | GM | HO | KL | NY | SZ | | | JCW | XEV | FGC | MGL | | |
| | | 13 | | | IV | III | VII | | | 21 | 16 | 24 | | | AD | CZ | FR | GT | HQ | KM | LN | PY | SU | VW | | | MPW | HXY | IUV | DTP | | |
| | | 14 | | | V | VIII | VII | | | 24 | 11 | 16 | | | BW | CZ | DR | EV | FS | HT | IQ | MX | NO | PU | | | HTF | AJN | FMW | LGA | | |
| | | 15 | | | VII | IV | VI | | | 23 | 26 | 09 | | | AZ | BR | CS | DO | EX | FI | GN | HW | KT | PU | | | SLK | SIC | EON | NJZ | | |
| | | 16 | | | VIII | I | III | | | 12 | 10 | 23 | | | AT | BX | CE | DJ | FV | GP | HY | LQ | NO | RS | | | SSW | NEP | RFF | LLZ | | |
| | | 17 | | | V | IV | VI | | | 08 | 26 | 06 | | | BD | CW | EF | GX | HP | IN | JU | KQ | LT | SY | | | WFA | EKH | VRF | CZW | | |
| | | 18 | | | II | I | V | | | 03 | 16 | 26 | | | AR | DV | EX | FM | GQ | HP | JY | KN | OU | SZ | | | VFS | LZZ | IPF | RJD | | |
| | | 19 | | | VII | II | VI | | | 21 | 18 | 25 | | | AZ | BM | CP | DR | EN | GY | IW | JO | KX | TU | | | ARL | CMV | FEN | IKZ | | |
| | | 20 | | | VII | II | I | | | 02 | 14 | 20 | | | AP | CE | DR | FL | GX | IT | JS | MO | NU | WZ | | | IIR | NRU | GGI | JEV | | |
| | | 21 | | | I | V | II | | | 05 | 14 | 10 | | | AF | BV | CY | DT | HM | IW | JO | LN | PQ | SZ | | | TTH | EKS | VKK | BDY | | |
| | | 22 | | | III | VI | VII | | | 17 | 13 | 09 | | | CX | DL | EJ | FY | HZ | IO | KU | MW | NT | PQ | | | RTM | AVC | BIV | KOY | | |
| | | 23 | | | I | V | IV | | | 01 | 05 | 04 | | | AN | BO | CP | DQ | ER | FS | GT | HU | IV | JW | | | BLE | TCH | LEY | PRK | | |
| | | 24 | | | II | III | V | | | 25 | 05 | 23 | | | AJ | CS | EU | FQ | GH | KX | MZ | NR | OT | PW | | | DHZ | WVF | NQU | RGF | | |
| | | 25 | | | II | IV | I | | | 20 | 25 | 07 | | | AS | BF | CP | EM | GJ | LW | NR | OT | QY | UZ | | | QTO | RDC | CSL | IGR | | |
| | | 26 | | | II | I | IV | | | 14 | 01 | 02 | | | AR | CN | DT | EL | FY | HM | IP | JV | KX | OW | | | KFS | TXQ | ZVJ | OTF | | |
| | | 27 | | | I | VIII | IV | | | 17 | 22 | 20 | | | AG | BK | CM | EJ | FW | HR | LO | NQ | ST | UX | | | WAP | UMY | SUR | CCI | | |
| | | 28 | | | IV | VI | I | | | 10 | 17 | 20 | | | AN | CR | DI | EO | GW | HT | JX | KY | LV | PQ | | | MFM | FNQ | RJZ | MRB | | |
| | | 29 | | | II | III | I | | | 21 | 15 | 07 | | | BI | CY | DR | FS | GP | HW | KL | MN | OZ | UV | | | WCD | MYF | URE | IKG | | |
| | | 30 | | | V | I | III | | | 19 | 06 | 04 | | | AJ | CS | DY | EI | FX | GL | HZ | KT | RW | UV | | | MJI | GRP | OBB | HYL | | |
|
The way to read the code table is as follows: once a recipient receives a message, he looks up the page in the code book for the current month, then finds the line in the chart that corresponds to the current day. Then s/he installs the rotors listed for that day 'in the prescribed order' with the rings installed also ordered as instructed. With that complete, s/he then configures the plugboard according to the letter-pairs noted for that day. And finally, s/he sets the rotors to the first key starting position. The machine is now ready to use.
Decryption
The operator sets up their enigma machine according to the day's instructions in the codebook, then enters the first three letters of the encrypted message. For example: HIT and note the unencrypted letters. Eg GEO - which is used for a second-level key. So, before doing anything else, the machine operator would re-set the starting position of the rotors to the new key. Eg. GEO. Then enter the rest of the message (omitting the first three letters). The result is the plaintext message.
There are many notes and caveats but we won't bog down our discussion except to say different branches of the military would use different key and pass-word schemes, and some even built in checksums to save valuable time. Also, some operators did not follow protocols properly and often re-used keys. And the keys should never be readable - like my example, which was done for the sake of easy reading and to clarify the concepts. Anyway, such deviations from strict protocol aided Allied decryption and should never be used during critical communication. For this cache, however, I will try to emphasize the process over obfuscation. Never fear, you'll have your work cut out for you either way, but I'll make it easier wherever I can. For example, the plugboard will use Caesar letter-pairing, and rotors and other settings will use predictable if not familiar values. Once you've succeeded in obtaining the message you can then use your imagination to appreciate just how difficult the process 'could' be made.
The Puzzle
Without further ado, discover the puzzle-message which will lead to the final cache location by decrypting the following ciphertext.
VSIVA LXAGN AAFNK GAGPF UPVXH RTPNE IZVCG WEPNW MXCEW FSMEY IPWMG FRVLA PLYRZ KLMNE EPSBT QRZRT VAWNW GCHHC DILTJ MVQXR VWKNU EGQOB FQFZR PQXHN DFWKE ZCHLF WPDSC KQLQP BIBKE HXHON VOCXB OKIER JULEY PESCU PPOVR IAIMK SVYQH NFFSO GVDAT YZSXQ WDMOY OJCDE DSNQC QIWIA RYQAO REMVB XYTLO ZALPD TVBCW SPWCA BIIRI BXVOM QDEFR VKYJY DXLDY KPZAF WDVZS DUYRZ TJAXU RTNJG AZUPO SGJKE ZKUJD VSRQF CAIBK HOJDH FQRBY ELWPK XVCFW NJEEU TKQMV AXUBU RDMZL BTHSP SGMHN IUKNR HKUHS EWVVS MGJOE ZHUXR OFQWM TXJBU YCUCL SVFMJ BUIFL IQJXZ QPTLU QIPTX BEVXB QVUMM JHCSN TIPFW KOJHL BINWY PTSYC XYOEQ YGKHO INVMN KMAJQ JAYWB NFLOI HFVHL MVGCF CTCGG MMDEU MPNNE YHINC LDNSY GGBOY RXJYI JIQJJ NNFYG JZJKL KPJKR GYQFK UADAZ IVWFW SCDPP QBFFS XTTMW BPUBU NYCTC MTWQL PUXMT QFJQV UAGID NNYYV SKTJV VUGEV CIKBQ QHWJV PUVAK UBNQN DABRY NWYHS VNBUI KDGXB QWFNF DLMWK URXSX VHXKE CYEBV BJWXV FADLK TDOQX LDLYQ AEFPC AKXAP UUSPF LUHKJ ZZQTC YCFST MYAJV EMNSW
Engima configuration:
- use the German Naval (Kriegsmarine) Enigma Machine (M3, UKW=B),
- use the codebook page above,
- the anniversary of Alan Turing's birth is the cipher date,
- the ciphertext includes a straight-forward three-letter key as described above.
Good luck, and by all means have fun.
Resources and Tools
Disclaimer: All links noted above worked when this cache was created. Over time, should any link break then you can usually find extra information here or with a simple web search. Note. Some sites offer executable windows-installable enigma machine emulators - some of them quite brilliant - but please be wise and explore the use of such programs at your own risk.