On January 5th, 2012, the following cryptic message was posted in the paranormal section
of an infamous Internet message board. Hello. We are looking for highly intelligent individuals.
To find them, we have devised a test. There is a message hidden in the image. Find it,
and it will lead you on the road to finding us. We look forward to meeting the few
who will make it all the way through. Good luck. 3301. And so would begin the most complex and
maddeningly difficult challenge that the Internet had ever seen. While at first some wrote it off
as a clever marketing stunt, over the span of the next ten years it would become increasingly
clear that it could be no such thing. But what, then, could it be? Who, or what, was 3301?
Many speculated that the whole thing was a recruiting tool for an intelligence agency
like the NSA, CIA, or MI6. Others believed that perhaps it was a secret society or cult, but why
then the need for complex skills in steganography, cryptography, mathematics and so on? And what was
the purpose? Where did it lead to, and how far would it take those who followed the trail?
And to what end? Many would become obsessed with finding out. Where individuals would fail,
groups would form, bringing their collective power and expertise to bear on solving the puzzles.
But that always runs the risk of one individual in the group going rogue with a discovery.
Based on recently leaked information that appears to bear the correct PGP signature,
it would appear that at least one person succeeded in solving the riddle of 3301. But who or what,
precisely, did they find? All that and more today, right here in Dave's Garage. [Intro]
I'm Dave Plummer, a retired software engineer from Microsoft going back to the MS-DOS and Windows 95
days, and today we're investigating the one of the greatest technological mysteries that the world
had ever seen: Cicada 3301. It all began with that simple JPEG image posted to the web. It claimed to
contain a secret message, but how, and where? The file posted that day appeared to be a simple JPG
image, but hidden away within it was plain text, easily extracted from the file with Unix "strings"
command. When run upon the image, it revealed a messages string that contained a reference to
TIBERIVS CLAVDIVS CAESAR followed by text that had clearly been scrambled by encryption.
But what kind of encryption? The reference to Caesar implied that this was likely a simple
"Caesar Cipher", wherein each letter is offset by some number within the alphabet, or in this case,
ASCII code. If offset by 3, then A becomes D, B becomes E, and so on. A few iterations of the
cipher solver reveals that, sure enough, in the 3301 image each letter is offset by 4, and once
corrected, the result is a URL to an image hosting site. Each step was getting slightly harder,
and this trend would continue until the challenges became maddeningly obscure and difficult - and yet
some would persevere, even through the Mayan alphabet, disappearing ink, ancient poetry
and cryptic ruins. Loading the linked image into the web browser, we get an image of a duck. More
specifically, a decoy duck, and one that openly admits to being a decoy at that: The text on the
message reads "Looks like you can't guess how to get the message out". This text is actually our
one and only clue: combining guess and out to yield the name of the outguess tool, a program
that is able to hide and retrieve information that has been intentionally hidden within an image.
By changing a mathematically predictable set of pixels by tiny subtle amounts, the tool is able
to encode data within an image that can't be seen by the naked eye. As a contrived example,
let's say we decided to hide text in an image by offsetting the blue value in every 131st pixel
up or down by one bit depending on whether we were trying to store a one or a zero.
Because we're changing the least significant bit of the color least sensitive to the human eye,
it's going to be entirely imperceptible in most non-trivial images. And that's basically how
steganography hides data inside of an image in a manner that's hard to detect. The outguess tool
applies a number of techniques to extract that hidden data for you automatically. And indeed,
using the outguess tool we can extract a character string from the duck decoy's image:
"Here is a book code. To find the book, and more information,
go to https://www.reddit.com/r/a2e7j6ic78h0j/" Apparently, the next stage of the clue was hidden
within the subreddit. The header contained a numeric code of some kind and a picture of a
welcome mat. By applying outguess again, we would receive perhaps the single most important piece of
information that 3301 would encode: it's public PGP key. A PGP key is a private-public keypair.
Only the person with the private key can generate messages that will have a signature
that matches the public key. Thus, you can send the public key out freely and then anyone
at any point can use it to verify that a signed message you later send out MUST have been signed,
with mathematical certainty, by whomever possessed the original private key. Put more simply,
it's a foolproof manner of verifying that a message really did come from a particular sender.
And it meant that from this point forward, no one could pretend to be 3301. Only the person truly
in possession of the official 3301 private key could send officially signed messages,
so it became impossible for anyone else to impersonate 3301. A second image on the subreddit
also contained a steganographic payload that could be extracted with outguess. The message read: "The
key has always been right in front of your eyes. This isn't the quest for the Holy Grail. Stop
making it more difficult than it is. Good luck. 3301" The subreddit also contained encrypted
text messages, which were found to be a Vigenere cipher, where 0 is A, 1 is B, 2 is C, and so on.
Decoding the text in the subreddit revealed an ancient English tale by Thomas Bullfinch
on King Arthur and his quest for the Holy Grail. The original subreddit message header,
when translated from Mayan, is the key to use with the cipher. It all decoded to a phone number,
214-390-9608. When called, that number played the following message.
Besides pointing out that the group's numeric name was, in fact, prime in its own right,
this message sent investigators on a quick hunt to find two more prime numbers hidden somewhere
in the image. A few quickly noted that the height and width of the image, 509 and 503,
were also prime numbers. Combined and multiplied with 3301, they would yield the number 845145127.
With a .com appended, it led them to a website that contained an image of a Cicada and a
countdown timer. With outguess applied to the cicada image, the follow message was revealed:
"You have done well to come this far. Patience is a virtue. Check back at 17:00
UTC. 3301" Everyone following the puzzle was now confronted with the same fate: waiting for the
countdown timer to expire. It was apparently a way to start the race anew, with everyone at the same
point. What happened next would solidify 3301's reputation as an international group and largely
eliminate the possibility that this was all a ruse created by a single hacker. Was the image
of the cicada important? An interesting fact about cicadas is that while there are over 1500 species,
they generally gestate underground for periods of 7, 13, or 17 years. The most popular theory has
been that this is to eliminate competition amongst cicadas by reducing the frequency of how often
their various gestation periods would overlap with each other. Others have advanced the theory that
a prime gestation period would overlap less often with predators that emerged on a 2-year, 3-year,
or 4-year cycle, for example. Regardless of what evolutionary pressure led to the prime gestation
periods, it is likely that this characteristic - the prime numbers associated with the gestation
period - is why 3301 has used cicada imagery. Primes are incredibly important to cryptography.
When the countdown timer reached zero, the image changed. It now contained 14 pairs of
GPS coordinated scattered around the globe: California, Australia, Hawaii, South Korea,
Poland, and many more. In each of those physical locations could be found a poster,
in plain view, that contained an image of a cicada and a QR code. The sudden appearance and
world-wide distribution of the posters meant that at a minimum, cicada was a broadly distributed
group. Those who believed that 3301 might simply be a few hackers in the basement now were faced
with the reality that at a minimum, 3301 had the resources to make a physical appearance in 14
international locations within a reasonably short time period. But how short? Assuming the posters
might last a week or two, they would have to be all placed within that time limit. A careful
analysis of the GPS locations reveals that most of the locations are within 90 minutes drive an
international airport, but this is true for most urban centers. It also meant that the puzzle was
now going "off the grid", or at least offline. To continue meant the solvers would have to
venture out into the real world. There were two variants of the poster. The QR code on the poster
led to an image from which could be extracted a riddle and taken as a whole they contained
new book ciphers and a curious admonition: "You've shared too much to this point. We want the best,
not the followers. Thus, the first few there will receive the prize. Good luck. 3301"
There was only one problem: the book ciphers were plain enough except that the messages never
indicated to WHICH books the ciphers should be run. The hunt was now on to find the very
books which would contain the encoded message. It would take centuries to do so by hand in even a
modest library, but thanks to the power of the internet and modern search, both were found in
reasonably short order. The first was found to be Encyclopaedia Britannica, 11th Edition,
Volume 6, Slice Number 3. The second book was even more obscure: though written by popular
author William Gibson, the book Agrippa was only released in a book printed in disappearing
ink and on self-erasing 3.5 inch floppy disc back in 1992...and no, I'm not kidding. The book
was literally printed on photosensitive paper, whose pages, when exposed to light even a single,
would the fade to nothingness. The floppy would entirely encrypt itself after a single use.
The result of these puzzles was a link to a page on the web. But it was Tor link, meaning it was a
link to the Dark Web. The Dark Web, for lack of a more thorough explanation, is largely encrypted,
secret, and unindexed. You generally don't surf it, you go directly to it for a particular page.
The reasons for a page's existence on the dark web range from a severe need for privacy to pretty
much every illegal activity imaginable. You can't get there accidentally with a regular web browser,
in fact. You need special software such as the Tor browser. The Tor link led to a message that
read: "Congratulations! Please create a new email address with a public, free, web-based service.
Once you've never used before, and enter it below. We recommend you do this while still using Tor,
for anonymity. 3301" It further explained where to send the email, but shortly after,
the message was replaced the following: "We want the best, not the followers."
Those who did so promptly received an email that lead to a page that contained an image of artwork.
That artwork contained a message with a link that purported to offer latecomers a second chance.
It also contained text that encoded another Tor link, which, via a series of prime numbers and
other puzzles, ultimately led to an audio file, known as a MIDI file. The musical contents of
the audio file seem unimportant, but the MIDI file contents could be laboriously decoded to produce
the next message: "Very good. You have proven to be most dedicated to come this far to attain
enlightenment. Create a gpg key for your email address and upload it to the mit key servers
then encrypt the following word list." It also provided a gmail address to send the encrypted
results to. Those who did so promptly were provided with an interesting amonition by email.
"Each person who has come this far has received a unique message encrypted with a unique key. You
are not to collaborate. Sharing your message or key will result in not receiving the next step."
Those whom were selected were also provided with a Tor link, this time to login page.
For the vast majority, as far as we know, this is where the trail went cold.
Once month later, the following message appeared on the subreddit.
"We have now found the individuals we sought. Thus our month-long journey ends. For Now.
Thank-you for your dedication and effort. If you were unable to complete the test, or did not
receive an email, do not despair. There will be more opportunities like this one. Thank you all.
3301." A select few, however, received the following explanation. In at least one case
it was leaked to the web, which is how we know of its existence. "We are not a hacker group.
We do not engage in illegal activity, nor do our members. If you are engaged in illegal activity,
we ask that you cease any and all illegal activities or decline membership at this time.
We will not ask questions if you decline. However, if you lie to us, we will find out."
"You are undoubtedly wondering what it is that we do. We are much like a think tank, in that
our primary focus is on researching and developing techniques to aid the ideas we advocate: liberty,
privacy, security." Next, it produced three questions to be answered by email:
"Do you believe that every human being has a right to privacy and anonymity?" "Do you
believe that information should be free?" "Do you believe that censorship harms humanity?"
Nothing more was heard from 3301. That is until precisely one year later, when,
on the anniversary of their original image, the next puzzle appeared.
Make sure you're subscribed to my channel for part 2, where we learn about the encypted Liber
Primus and the man who ultimately cracked the 3301 puzzle and was offered a chance
to join. All next time, right here in Dave's Garage.
[https://votiro.com/blog/image-steganography-example-how-i-created-an-attack/]