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Computer science theory
Course: Computer science theory > Unit 2
Lesson 3: Cryptography challenge 101Clue #3
So you take a stroll to the train station...
You don't see anything under the bench...
What's that over there?
Clue #3
Hint 1: Visual Telegraphs
Transcript of the above message:
44541134541123335344541242
43424432514121231131135315
54425442444243443251415343
54324234411125513553341342
43225343114454345343225134
31421432513412533412155415
34513351444411225144425442
44441534512355154321345111
13112123514254315333214243
51445315341434512542531544
335154325341443
(cut off)
43513544
Want to join the conversation?
- I tried getting the most out of the message, just to be easier for decrypting.
44541134541123335344541242434244325141212311311353155442544244424344325141534354324234411125513553341342432253431144543453432251343142143251341253341215541534513351444411225144425442444415345123551543213451111311212351425431533321424351445315341434512542531544335154325341443...(missing)...43513544(232 votes)- Thanks! This'll make decrypting it a lot easier!
I finally figured it out!(73 votes)
- I understand this is a polybius square, and it seems there's no "Z", as per reading the questions here, but what's the arrangement of letters? I've solved clues 1 and 2, and they're all plain English, but don't hint about the letter arrangement... Does it have to do with clue 2's keyword?
Assuming the message begins with "start", I've figured out four letters in (x, y) format, such as 54 being (5, 4), but can't figure out how to do the rest of the letters.(8 votes)- If you draw the polybius square, and enter the letters for 'start' in the positions that you think they belong in, the arrangement of these letters in the square should give you an idea as to the overall pattern of how letters are arranged in the square. (Hint: What is the pattern that r,s,t make in this square ? If you had to guess, where would you put q? what about p?)(23 votes)
- So this one is multiple layers of code... unless this time they don't use the message format we have been using for our advantage?? what about the address number has to mean something! what do u think?(7 votes)
- I've been trying this for a while now and can't seem to get anything to work out. It must be multiple encryptions (i.e. the square and polyalphabetic or something) but everything I try comes up with nothing. The thing I can't get though is that the last message they only said about adding the square. If they have changed to other methods or other keys surely they would have mentioned that? Other wise the person who just received this message would be in the same position as we are?(8 votes)
- Wow! I watched the video and *'BAM'* , I got the answer for the 3rd clue. The same exact thing is shown in the video! HINT - There are only numbers from 1-5 in the message. But as in the 1st clue @Noble Mushtak told me that the door number ( 250 ) had something to do with the decryption . I wonder if *'3815'* is also some kind of clue?? If anybody knows a decryption method related to 3815 , please tell me!(8 votes)
- I wondered if this was relevant too. I didn't find anything, but I didn't catch the 250 thing either. I wouldn't worry about it too much.(3 votes)
- Did anybody get a bunch of random letters for the last word? I have the entire message but the last 5 letters are nonsense.(6 votes)
- I did until I realized that the '3' on the end of the line above is half a letter and stripped it out. Without that, it's a recognizable word. Try just '43513544'.(6 votes)
- I hope randomly clicking helps in getting the points :)
What is a good Hint for this?(4 votes)- Watch this video: https://www.khanacademy.org/math/applied-math/informationtheory/info-theory/v/history-of-optical-telegraphs--language-of-coins--5-9
I think that in there, it explains what a Polybius square is.
Once you know what a Polybius square is, look at the message. This message is encrypted with a Polybius square. There is no Z in the message. The first word is the same as the first word in Clue#1 and Clue#2.
Look around the discussion page for more hints!(5 votes)
- does this give us another encrypted message or have i done it wrong?(3 votes)
- Remember that in coordinates, the horizontal coordinate is placed before the vertical coordinate...and that this ISN'T coordinates.(6 votes)
- OK, so on the Clue 3 image, I see a ton of lightning bolts instead of numbers.
I cannot tell if those are supposed to be 3's or 5's.
Can someone please help out? Thanks.(3 votes)- The "lightning bolts" are 5s.(3 votes)
- I still don't know what to do even after reading the other hints.
I used the polybius square and got the result.
Then I tried a keyword that made the first word, start.
The rest doesn't make sense.
Can I have some tips to how to keep going?(3 votes)- Try to make a polybius square using the 26 letters of the alphabet. Then, using the positions of the letters of the first word in the square, try to find out where the other letters would go.
Hope this helps!(2 votes)
- You seriously need very good patience to do all of this decrypting , which I currently don't have! I don't think that there is a program in KA which can make this easier! If anybody has a KA or Java program on this please send me the link!(2 votes)
- I think the best way to approach these types of challenges is to start by doing it long hand. This will help you to better understand the process. After you understand the process (or think you do) build a tool/program for yourself to take care of the tedious/repetitive stuff.
The long hand part is monumentally important. It helps you structure an outline for programming the tool in an effective way.
If you don't think you can make the program yourself, take a breather from cryptography and head over to the computer science (https://www.khanacademy.org/cs) section and start learning. it is a LOT of fun, and can be a very powerful tool to learn.(4 votes)