7 ms·
If you have zero experience in cryptography, how would you go about learning the necessary to crack this?
by carlsednaoui 13y ago
If you have zero experience in cryptography, how would you go about learning the necessary to crack this?
- deif 13y agoA good think about how you would exchange letters can solve this code as they've just given you the most simple example. You could read through a few ebooks available on cyptography freely on the internet, but you don't even need to do that in this case, I could just tell you. The most common letter used in the english language is 'e'. Now identify the dot pattern that is the most common. Voila, you can translate a lot of the code. For the other letters, I would investigate some sort of chart that ranks the most common letters in the English alphabet. With a bit of playing you can do this with a pencil and paper. Obviously computer cryptography is more advanced, but your question related to this code specifically.
- bluedino 13y ago> Obviously computer cryptography is more advanced Wouldn't a single message from an unknown cipher be almost impossible to crack? You'd either need to know the algorithm or have multiple encoded messages along with the keys, right?
- youngerdryas 13y agoA one time pad cipher can be considered unbreakable. http://en.wikipedia.org/wiki/One-time_pad http://en.wikipedia.org/wiki/One-time_pad
- nijk 13y agoNot necessarily, because some ciphers retain statistical information about the plaintext . any prior knowledge about the shape of the plaintext can give you better than flat random chance of recognizing he decrypt.
- jgrahamc 13y agoThis is a very simple code to break. Helen Fouché Gaines' book Cryptanalysis (published in 1939) is a good introduction : http://www.amazon.com/Cryptanalysis-Study-Ciphers-Their-Solution/dp/0486200973 http://www.amazon.com/Cryptanalysis-Study-Ciphers-Their-Solu...
- carlsednaoui 13y agoAwesome, thank you so much!
- kkkaaa 13y agoYou can also look for characters that are easily identifiable. For example, assuming the text is in english, there aren't many options for a word that uses only a single letter. So the single character in the fifth line is most likely an "I" or an "a". These can also go into your chart.
- laumars 13y agoSPOILER ALERT This looks like straight character substitution, so it's essentially just trial and error, but the best vector for attack is the following: Look at the shorter words first (2 and 3 character words), guess what one word might be, then match the same characters in the other short words. Once you have a few that seem to pair up, you can start building the longer words from the answers you've got from the shorter ones. Puzzles like this one isn't far off doing a crossword or sudoku. There isn't really a cypher to it, no maths etc. It's just having the patience to guess at a few placements then seeing if that fits the wider model.
- laumars 13y agoWhy am I being marked down for that? It's clearly marked spoiler so anyone who doesn't want tips can avoid it; yet in spite of that, I was very careful not to give any answers away. All I did was suggest techniques to crack the code. And most importantly, my post answers the question raised - which is the whole fucking point of a comments system. If anyone didn't want to hints then they should have just skipped over the post the moment they read "spoiler alert" rather than knee jerk reacting with a down-vote for a post that others might have found helpful. I swear to god the use of the peer review system on HN has been in steady decline over the last few years.
- rubinelli 13y agoIf you want a basic primer using python: http://inventwithpython.com/hacking/index.html http://inventwithpython.com/hacking/index.html
- carlsednaoui 13y agoThis is great! Im going to see if they have something similar for Ruby (if not, then Python time it is!). Thanks!
- youngerdryas 13y agoSimon Singh's "The Code Book" is a good overview and well written. http://www.amazon.com/The-Code-Book-Science-Cryptography/dp/0385495323/ref=sr_1_1?ie=UTF8&qid=1367588416&sr=8-1&keywords=The+code+book http://www.amazon.com/The-Code-Book-Science-Cryptography/dp/...
- carlsednaoui 13y agoThank you, I'm definitely going to check it out!
- Someone 13y agohttp://en.wikipedia.org/wiki/Cryptanalysis http://en.wikipedia.org/wiki/Cryptanalysis, http://www.fbi.gov/about-us/lab/forensic-science-communications/fsc/jan2000/olson.htm http://www.fbi.gov/about-us/lab/forensic-science-communicati... I would think anybody even remotely interested in encryption would know about this 'encryption' (I use the term loosely) method. I also think such persons would have spotted that this might be a form of that method within a minute, but apparently, I am wrong about that.
- avparker 13y agoThere is the free "Cryptography 1" course on Coursera ( https://www.coursera.org/course/crypto https://www.coursera.org/course/crypto ). I'm taking it right now. There's a lot of maths and theory, and it's quite a difficult course, but it's been a great way to learn the foundations of cryptography.
- alinajaf 13y agoProbably a good a place as any to start: http://www.matasano.com/articles/crypto-challenges/ http://www.matasano.com/articles/crypto-challenges/