Cracking Episode 2's Element Code

[Osmium]

As I reached the end of episode 2, I finally got this "ace in the hole" that Fontaine was asking about. It was the only one of Suchong's encoded notes that isn't immediately translated for the player so I got curious and paused the game to crack the code on my own. I had to reload the checkpoint twice just to write down the whole message because it's only onscreen for a moment. My only clues were the message itself (P, F, V, K, Ar, Mg, Sc, Al, B, Na, Sc, Ar, Mn, B), Elizabeth's reaction when she read it ("*scoffs*, That's what this was all about?!") and something Elizabeth says earlier in the episode about the code.

Just after you find the rift machine in Suchong's lab you come across a set of blueprints with a bunch of pseudo-chemical compounds drawn on it. Elizabeth get into a conversation with Booker about it, explaining that this is actually a code, with each symbol matching an element on the periodic table. You take the atomic number for the element corresponding to each symbol to tell you which letter in the alphabet that element matches with. For example P is Phosphorous, the 15th element so that is the 15th letter: "O". F is Fluorine, the 9th element, giving you an "I". Applying this to the encoded message gives you OIWSR LUM EKURYE. However, if you stop there, the message is still jumbled because there is a further level of encryption applied to the code. Elizabeth explains that this is a Vigenere cypher, which means you need to use a codeword, which she points out as being the guy's name: SUCHONG.

So how the heck does a Vigenere cypher work? Basically you take each letter of this password and replace it with that letter's place in the alphabet. S is the 19th letter in the alphabet, U is the 21st and so on. SUCHONG gives you 19-21-3-8-15-14-7, which you THEN use as instructions for translating the message. Starting with the partially decoded message OIWSR LUM EKURYE, you look at the letter that is 19 places before the O, which gives you a V, since once you reach A you start again at Z and keep going backwards until you've gone the appropriate number of spaces. Then, you do it again for the next letter "I" by going back 21 spaces, giving you an N. Repeat for each letter and once you reach the G in SUCHONG start over from the S and keep going. If you show your work you get O - 19, I - 21, W - 3, S - 8, R - 15, L - 14, U - 7, M - 19, E - 21, K - 3, U - 8, R - 15, Y - 14, and E - 7. Once you do this, you get the message VNTKC XNT JHMCKX

Wait, WHAT?! I thought we were done! Don't despair, we're almost there. I thought I had made a mistake at this point and rechecked all of my numbers and even checked an online Vigenere decrypter to make sure. Once everything checked out, I stared at the message VNTKC XNT JHMCKX and it suddenly clicked that there was a THIRD level of encryption: a ROT1 cypher. Fortunately this is the simplest kind of cypher, and just requires you to replace each letter with the next letter in the alphabet. V becomes W, N becomes O and so on until you get the TRUE message: WOULD YOU KINDLY

I slapped my forhead once I finally got to the end and said "Of course! Why didn't I guess that sooner?" When I got back to the game I found out that Elizabeth translates it at the end of the episode, but I really enjoyed working this out on my own before then. I'm impressed that the game developers actually invented this code and put it in the game, even though 99.9% of players would never verify that it says what Elizabeth says it does. I'm even more impressed that Elizabeth does all this in her head in less than 3 seconds when it took me over an hour and an entire sheet of notebook paper!

I have no prior background in cryptography, so I had to learn as I went.

[Solarmech]

Well done! If we had rep in here you would have earned it. sm

[Blewris]

Nice. Was a good read :)

[Ivlichnov]

An impressive amount of work there. Well done.

And I really like the amount of depth that there is to the Bioshock series.

[IamNotMe]

Great work man, just one thing - I don't think there's a third level of encryption, when numbering the alphabet you assigned 'A' to 1, if you start 'A' from 0 rather then 1 it will give you the answer without having to ROT1 decode. :D

[Osmium]

Publicado originalmente por IamNotRahim:

Great work man, just one thing - I don't think there's a third level of encryption, when numbering the alphabet you assigned 'A' to 1, if you start 'A' from 0 rather then 1 it will give you the answer without having to ROT1 decode. :D

Thank you, that makes a lot more sense and simplifies some of the stuff towards the end. I kind of went around my elbow to get to my thumb on that part, lol.

I think the reason I used A=1 in the second half of the code is because the letters from the first part of the code come from elements 1-26, Hydrogen through Iron. I couldn't start at 0 there because there is no element 0 (this isn't Mass Effect, after all). I overlooked that step where I needed to separately set A=0 for the purposes of the Vigenere cipher. It seems to be necessary to make the modular arithmetic line up but I don't really understand why.

[Mandelbrot]

1) Heard of screenshots? They can make the decryption process much easier because you don't have to keep reloading the checkpoints!
2) I believe that I read somewhere that the earlier codes in the game are NOT actually what they are shown to be in English. The actual decrypted text goes something along the lines of 'We should replace this with something important eventually'.

[Solarmech]

Publicado originalmente por Mandelbrot:

2) I believe that I read somewhere that the earlier codes in the game are NOT actually what they are shown to be in English. The actual decrypted text goes something along the lines of 'We should replace this with something important eventually'.

That was only for one of the messages (The one Old Elizabeth gave to Booker IIRC). All the other messages have been real. sm

[Mandelbrot]

Publicado originalmente por Solarmech:

That was only for one of the messages (The one Old Elizabeth gave to Booker IIRC). All the other messages have been real. sm

So the following messages were all valid ciphertexts for the shown plaintexts?
1) The tear machine schematics code
2) The big daddy imprinting experiment codes
3) The ace in the hole

If so, can you state your sources?

Thank you

[Solarmech]

The FIRST post showed that the cyphers are real. After all if they where not then we would know it. sm

And here is the evidence for the cypers being real and that the one old Elizabeth gave Booker was a stand in. http://bioshock.wikia.com/wiki/Vox_Cipher

[Mandelbrot]

The FIRST post showed that the LAST cipher with the ace in the hole was real.
At any rate, Osmium, if you want to actually try to decrypt the other SUCHONG Vigenere ciphers, go ahead.

[Osmium]

Yes, I've gotten more in the habit of using screenshots recently. It does help with these sorts of investigations. At the time I took screenshots so infrequently I'd forget that it was a feature both in my computer and within the steam client.

I did solve the cipher for at least one other phrase from Suchong's lab. I tested the phrase "cathode tube" to make sure that I was applying the cipher correctly and it really does say "cathode tube". Well, at the time I wasn't adjusting the proper amount and it technically said "bzsgncd stad". That's how I found that I was one letter off and needed the ROT1 to compensate for my earlier mistake.

I don't have either the game or the DLC installed anymore, so I'd have to watch a let's play on Youtube or something to verify the rest of the codes. I think it's quite plausible that they are all legit.

[Solarmech]

You can get the coded messages from BaS Ep 2 on the Bioshock wiki.

http://bioshock.wikia.com/wiki/Coded_Messages

The staff there went over these already. A contributer there UpgradeTech (a GREAT person) has delved deeply into these. sm

[Osmium]

The wiki has a couple screenshots with the codes about the Big Daddy but doesn't have the tear machine schematics. Since Mandlebrot is really twisting my arm with insisting scientific rigorousness, I feel I really have no choice but to verify the remaining codes ;). I found them on youtube and took a picture myself: http://imgur.com/xPvRCNC

The codes are as follows:
Sc Sc Ti P Li Cl Na Mg P Be Mg (21-21-22-15-3-17-11 12-15-4-12)
Cl He2 Mn Sc Mg V F S Ar Cr (17-2 25-21-12-23-9-16-18-24)
K O C P K Si Fe Na Li S Ar (19-8-6 15-19-14-26 11-3-16-18)

The SUCHONG key, setting A to 0, is (18-20-2-7-14-13-6). Keep subtracting these numbers, in sequence, from the sets above. Treat all 3 lines as one code and repeat the key until you've finished the page. If, when subtracting, you get a negative number, then add it to 26 (e.g. 3 - 14 = -11 + 26 = 15). Then resubstitute each number with its place in the alphabet, A=1, B=2, etc.

3-1-20-8-15-4-5 20-21-2-5 = cathode tube
3-15 19-3-18-21-2-2-5-18 = CO2 scrubber (the 2 is shown in the element part of the code)
1-14-4 8-5-1-20 19-9-14-11 = and heat sink

And just to check our work, here's Elizabeth's decryption, that she does in her head in moments:
http://imgur.com/76c9dh9
Checks out!

[Mandelbrot]

Publicado originalmente por Osmium:

Since Mandlebrot is really twisting my arm with insisting scientific rigorousness, I feel I really have no choice but to verify the remaining codes ;).

Twisting your arm??? This is what I said:

Publicado originalmente por Mandelbrot:

At any rate, Osmium, if you want to actually try to decrypt the other SUCHONG Vigenere ciphers, go ahead.

I 'suggested' that you do it, while hinting that I would appreciate it if you did it.

Anyway, this means that the devs believed that there would actually be fans determined enough to actually decrypt the code themselves.

[Osmium]

I was being facetious, hence my winking face ;)