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| Can Anyone Break This???? | |
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| Topic Started: Mar 30 2008, 05:32 AM (705 Views) | |
| Paarth Dave | Mar 30 2008, 05:32 AM Post #1 |
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Advanced Member
  ![]](http://209.85.122.85/static/1/pip_r.png)
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Can anyone break this? I hope not...... This is one of the best ciphers I have ever made...... Dd31s(97)^2N23*17+67-L83^97!11e79-23n37/89#53~19 Hint: '-' signifies break between words.. 
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Cryptography Vanquished.... | |
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| Paarth Dave | Apr 2 2008, 07:49 AM Post #2 |
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Hints: ->This cipher is surprisingly a simple substitution cipher. ->To find out the substitution, you will have to think something different. ->Some characters in this cipher are of no use. |
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| Paarth Dave | Apr 6 2008, 07:21 AM Post #3 |
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No Takers? I thought this forum is full of professional cryptographers...... |
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| jdege | Apr 6 2008, 04:38 PM Post #4 |
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You thought wrong. We're a bunch of amateurs. Of various degrees of aptitude and experience. We all have our own lives, and our own interests, and only a limited amount of time to spend on this hobby. Spending a time trying to cryptanalize a novel cipher is something some of us might attempt, now and again - if we think we might learn something useful in the process. If you read through the archived posts you'll find a few examples of this. But there's a fundamental difference between trying to cryptanalize a new cipher that has some novel features, and trying to guess the exact cipher used given only a short bit of ciphertext, with no evidence that there will be anything novel about the cipher used. Particularly when the cipher text provided appears to be shorter than the unicity distance. Like I said, if you want people to spend any time at all examining your cipher system, provide a full explanation of the method. Take a look at Donald's submission of his "Spread" cipher in Crypto->Cryptograhy->General: The "spread" Cipher, a cipher I'm playing with Don't just throw ciphertext at us. It's a waste of our time. |
| When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl. | |
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| Paarth Dave | Apr 7 2008, 07:54 AM Post #5 |
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No problem, buddy....I'll teach this ciher to all of you....And I promise to explain all my ciphers in the future..... This cipher is named "Draconian Devil" and it goes like this..... My cipher system is based on prime numbers..... There are 26 prime numbers from 1-100 and I have taken each letter of the alphabet and substituted with each prime number from 1-100 in a different manner..... Instead of A=2,B=3,C=5....and so on.... it is Z=2,Y=3,X=5.......A=97... But you may all wonder about symbols and alphabets in my ciphertext...... Interestingly, they are simply useless....I have just added them to confuse people... And, ya, 1 more thing....When 2 same letters appear together, for eg, 'AA' then the ciphertext will here be (97)^2....... So solving the above ciphertext is now very simple... It reads Paarth Dave Rocks Now here's a challenge for you all..... |
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| Paarth Dave | Apr 7 2008, 08:02 AM Post #6 |
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xtar89[]lam37,,41!0+71\23#97!siuAD17~13*47HMAQss(97@17{61}37&41%19-- This is gonna be easy.. |
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| jdege | Apr 7 2008, 12:42 PM Post #7 |
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So, simple substitution, with nulls, but with a single, fixed key? Once you explain it to us, the explanation provides us with all the information we need to decrypt? The crypto community abandoned those hundreds of years ago. The problem is that once you know how the system works, you can read the messages. And you have to explain how the system works to all your code clerks. A system that depends upon none of them revealing the system, or accidentally leaving the instructions lying around, is a system you can't depend upon. Remember Kerckhoff's principles:
Notice 2&3 - the goal is to devise systems in which everything can be known about the system except for the key, without compromising the system. If the enemy discovers how the system works, you should not be compromised. If a key is compromised, you simply use a different key. You know, many years ago I invented my own "unbreakable" cipher, based on prime numbers and a 26-letter alphabet. I noticed that 3+5+7+11 = 26. So I used a keyword to create a permutation of the alphabet:
I'd write out the alphabet in columns, the first letter in each column being a letter of the keyword (with duplicates removed), and the rest of the alphabet written out in order beneath.
They'd then be read out in columns, in alphabetic order of the columns..
This, then, would be broken into four keywords, of lengths 3, 5, 7, and 11.
These would then become the keywords of four independent vig ciphers
So the ciphertext would be:
What I had been thinking was that since the longer the keyword, the longer the period, and the fewer the repetitions, using multiple keywords with lengths that were relatively prime would be the same as using one long keyword, without the hassle of having to remember it. 3 * 5 * 7 * 11 = 1155 - quite a long keyword. So I thought this would be difficult to break. It's certainly more difficult than a standard vig, but it's by no means impossible to break. |
| When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl. | |
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| jdege | Apr 7 2008, 07:27 PM Post #8 |
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BTW - there are only 25 prime numbers between 1 and 100. |
| When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl. | |
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| Paarth Dave | Apr 9 2008, 06:38 AM Post #9 |
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I know this system of mine is not so secure....But in this modern world of encryptions, people try to think big and complex...Had I posted a ciphertext of mine on the Net, people would never have thought that the key would be so simple...The mentality of people has changed...they can't think simple...They feel that as the ciphertext looks so complex with different characters, the key to this must be complex, too.
No...there are 26 prime numbers.... They are as follows: 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,91 and 97.. And, ya, Thanks for those principles....
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| jdege | Apr 9 2008, 11:56 AM Post #10 |
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91 isn't prime. And as far as "as the ciphertext looks so complex with different characters", I expect that anyone with any interest in crypto - certainly anyone who might try to crack an unfamiliar cipher - knows enough not to be thrown by an unusual character set. More than 150 years ago, when Edgar Allen Poe first published his challenges to the readers, he claimed that he'd be able to break any substitution cipher, no matter how outlandish the character set. In truth, he didn't know much, but he did know that the symbology was of no relevance whatsoever. (He published one example of a cipher that he couldn't break, explaining to his readers that the author was engaged in a fraud, "proving" that it couldn't have been a real cipher. In fact, it was encrypted using a Vigenere cipher, instead of simple substitution. Oops!) |
| When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl. | |
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| Paarth Dave | Apr 9 2008, 04:10 PM Post #11 |
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OK, if 91 isn't prime....I can add 1 to the list...and then Z=1, Y=2, X=3....and so on.. Anyways, this is only a paper-and-pencil cipher and if not secure, shouldn't be used at first. I was just experimenting on such ciphering systems.. |
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Cryptography Vanquished.... | |
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| jdege | Apr 9 2008, 06:22 PM Post #12 |
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None of us are doing more than playing around with ideas that strike our fancy. Some people like breaking Aristocrats (simple substitutions preserving word division) over and over. I find it tedious. My goal is to progress to more and more sophisticated ciphers. That said, I've not yet managed to figure out how to break Patristocrats (simple substitutions without word division) reliably. Aristos I can find a hook into almost immediately, in all but the most perverse* cases. With Pats I can find an immediate hook only about a third of the time. So while I intend to eventually explore methods for cracking more sophisticated ciphers, at present I'm continuing to bang my head against the Pats. *By perverse, I mean plaintext chosen to intentionally make things difficult, i.e.:
[/SMALL] |
| When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl. | |
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| Paarth Dave | Apr 10 2008, 01:49 PM Post #13 |
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What do you mean by a perverse? I don't get anything of what you have posted as a code.... |
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Cryptography Vanquished.... | |
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| jdege | Apr 10 2008, 03:33 PM Post #14 |
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A good cipher is one that makes it difficult to break any message. But even a weak cipher can be difficult to break, when the plaintext is intentionally chosen to mislead. That is - people who are using ciphers to protect their sensitive communications have to encrypt messages that are part of that communication. People who are using ciphers as a game, to challenge people who break ciphers for fun, are under no such restriction. So you often see, in crypto puzzles, plaintexts chosen to make difficult the life of the crypto buff who is trying to break it. It is possible, if you are familiar with the techniques used to break a particular cipher, to choose a plaintext intended to make those techniques inapplicable. What do people use to break simple substitutions? Letter frequency, digram frequency, short words, pattern words, etc. The ACA's "Cryptogram" has 25 Aristocrats in each issue. The last five are usually of this form - texts chosen with the intent of making the normal techniques of breaking substitution ciphers difficult. A message consisting only of words of six letters with no duplicates, so that pattern word matching is useless. Or a message such as the one I quoted, with an absurd number of repetitions of a normally very low frequency digram. What I quoted wasn't ciphertext, it was plaintext of a type that would produce ciphertext that would be resistant to the ordinary attacks. |
| When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl. | |
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| Paarth Dave | Apr 10 2008, 03:52 PM Post #15 |
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This is very interesting.... Anyways, what would be the ciphertext of the code you have posted just above????? Will it be simple substitution with Patristocrats or something else?? |
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Cryptography Vanquished.... | |
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