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BSF Cipher Challenge

Posted: Sun Aug 31, 2008 11:17 am
by DoubleThink
CURRENT STANDINGS:
Leader-Jafo-1 point.


Ok, I've been reading up on codes and ciphers, and figured it might be a fun exercise for us to have a Cipher Challenge.

Once a(n) (arbitrary length of time), I will post a new ciphertext for you all to decode. It will use a historic code or one I have made up, and will be entirely possible to solve. First person to completely decode it gets a point or something.

I strongly discourage 'cheating,' i.e. using a computer program to brute-force the ciphers. This is about testing your analytical and mathematical capabilities and stuff like that.

First ciphertext is the following:

Code: Select all

GHPBLMAXPBGMXKHYHNKWBLVHGMXGMFTWXZEHKBHNLLNFFXKU
RMABLLHGHYRHKDTGWTEEMAXVEHNWLMATMEHPKWNIHGHNKAHNLXBG
MAXWXXIUHLHFHYMAXHVXTGUNKBXW
I hope that's not an overwhelming amount. In fact, more characters would actually make the decryption [size=0](Read: Frequency Analysis) [/size]easier, but I don't want to scare the crap out of you guys before stuff actually gets challenging. If you don't like this ciphertext, then feel free to ask for a new one. If the common consensus is that we need a different encryption method, I'll get a new one. If there is not significant progress in (arbitrary amount of time), I will give hints.

First clue, just to get you guys rolling: It's a fairly famous speech.

Also, I recommend reading The Code Book, by Simon Singh. This is by no means necessary, but it is a pretty cool exploration of historic codes, and how they were solved in the past.

Posted: Sun Aug 31, 2008 11:54 am
by Water_and_Wind
Are letter-frequency programs allowed?

Posted: Sun Aug 31, 2008 12:04 pm
by DoubleThink
Frequency analysis is pretty much necessary.

I'm not going to lay down specific restrictions. All I'm really adamant about is that you don't go to an online engine and plug in the entire thing for translation. Use your own discretion. You don't really gain anything by doing less effort, and you ruin it for everyone, including yourself. As said earlier, my big no is a program that just brute-forces the cipher. No fun there.

Things will get more difficult from here, I promise.

Posted: Sun Aug 31, 2008 12:23 pm
by ChaosTheory
Excellent idea. What about spaces? Are there spaces in the text, are they represented by a different letter, or are there no spaces whatsoever?

I think ciphers with normal spaces are better for most people, unless you want to make it really hard. I used to make these for a contest we had at school - people looked at the wall of text and gave up.

So "I hit a home run" turns into "V JKO L JYFD NMW", not "VJKOLJYFDNMW", which could be any number of things.

Posted: Sun Aug 31, 2008 12:36 pm
by DoubleThink
Currently there are no spaces, but it should be irrelevant. Once it's translated, it will form obvious words, all that will be needed is punctuation. If it is really necessary for me to put spaces in, I will for simpler ciphers like the one above.

People. I've started with among the easiest ciphers of all. Just try it. It isn't terribly hard, you've all got what you need to get going.

Posted: Sun Aug 31, 2008 3:18 pm
by Jafo
Given your hints of the easiest type of cypher, I guessed that it would a straight forward substitution cypher.

My key which happened to work was to look for the repeating pattern for the word 'the', and found 'max' was there 4 times. I was typing it into an excel spreadsheet for a simple character to character translation and noticed that the 3 characters for 'max' = 'the' were an alphabetic shift. It resolved itself quickly from that and it was just tedious to do the substitution. (a -> h, b->i, c->j, etc.)

I thought I had made a mistake seeing a word that seemed to be 'lowrd' in the middle of the text, and had to look up the quote online once I found it to verify the word. Verified but some quotations have it as lour'd and others have it as low'r'd.

Anyways - here it is:

nowisthewinterofourdiscontentmadeglorioussummerb
ythissonofyorkandallthecloudsthatlowrduponourhousein
thedeepbosomoftheoceanburied

This is probably the limit that I can go to in decyphering.

Posted: Sun Aug 31, 2008 6:11 pm
by Empty
now is the winter of our discontent made glorious summer by this son of york and all the clouds that lowrd upon our house in the deep bosom of the ocean buried

That's what I get of the above post. I'm guessing it's quote but I've never heard it.

Posted: Sun Aug 31, 2008 6:37 pm
by Anna
Empty wrote:now is the winter of our discontent made glorious summer by this son of york and all the clouds that lowrd upon our house in the deep bosom of the ocean buried

That's what I get of the above post. I'm guessing it's quote but I've never heard it.
It's a quote from one of Shakespeare's plays, Richard III. That said, you actually didn't do anything except add in spaces to Jafo's deciphering, so I'm not sure wh you felt the need to post. You didn't do any of the work deciphering it at all.

Posted: Sun Aug 31, 2008 7:57 pm
by Empty
You didn't need to be an asshole, I never said I deciphered, I was just making it easier to read.

Posted: Sun Aug 31, 2008 8:13 pm
by Anna
If you think that's me being an asshole, you obviously don't know me very well. :lol: And anyone who needed you to add in the spaces for them obviously needs a refresher course in english, 'cause it ain't that hard to figure out.

Posted: Sun Aug 31, 2008 8:55 pm
by antisocialmunky
Empty wrote:You didn't need to be an asshole, I never said I deciphered, I was just making it easier to read.
Anna
Grumpy Old Shipbuilding Asshat

Its his nature. And now you know, and knowing is half the battle!

Posted: Sun Aug 31, 2008 11:57 pm
by Himura.Kenshin
I'm sorry you feel that way, Anna. I welcomed his post with the spaces put in... I was tired last night it and was relieved that I didn't have to strain my eyes to read it. So thank you, Empty.

Posted: Mon Sep 01, 2008 2:22 am
by DoubleThink
Ok. Point goes to Jafo, he actually did the work. (Inserting spaces doesn't count for anything.)

In the future, all plaintext answers will be expected to be punctuated to the best of your ability. My next cipher will be up soon enough, and will probably be the same design, just extended a bit further.

Posted: Mon Sep 01, 2008 8:05 am
by Empty
I never wanted any 'points' for it, It's just better in that format because it lets everyone know what it was without having to spend a minute or so correcting it. Doublethink, can we put in our own ciphers, or is it just you?

Posted: Mon Sep 01, 2008 10:23 am
by DoubleThink
I'm currently trying to keep the Cipher Challenge structured so that I can gradually increase difficulty. If you want a cipher included, please PM it to me, with a descriptive subject.

Next cipher is in the works, it will likely be of similar difficulty. Just a bit longer, so you get used to stuff. Steganography will also be featured in the future. \o/