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| Tutorial: Identifying A Cipher | |
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| Topic Started: Dec 18 2007, 09:31 AM (399 Views) | |
| Revelation | Dec 18 2007, 09:31 AM Post #1 |
Administrator
  ![]](http://209.85.122.85/static/1/pip_r.png)
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This will be the new tutorial about how to identify a cipher, If you have anything to add, please post a reply! I can't make this tutorial alone
 Step one: visual identification Sometimes you can see by the looks of the cipher what cipher it is.
Do not look at spacing if you see groups of words. The spacings are probably added manually and the true spaces have been removed. Step two: frequency counting In most languages one character appears more often than other characters. In English this is the 'e', then followed by 'taoi'. Some ciphers replace one character with another and this causes the frequencies to change. For example, if you replace the 'e' with a 'z' in a text, the z has an abnormally high frequency. If you find that the frequency of your cipher text differs much from this table  You're probably dealing with a substitution cipher. Note: This method works better if you've got a long cipher text. In short texts the frequencies may be really different. Example: That man is a qualified waiter. to be continued |
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RRRREJMEEEEEPVKLWENFNVJKEEEEEAOLKAFKLXCFZAASDJXZTTTTTTTLSIOWJXMOKLAFJNNKFNXN RAGRBAQEMHIGDJVDSEOXVIYCELFHWLELJFIENXLRATALSJFSLCYTKLASJDKMHGOVOKAJDNMNUITN RRRRLJVEEEEECLYVYHNVPFTAEEEEEMWLMEIRNGLARWJAKJDFLWNTIERJMIPQWOTZEOCXKNUBNXCN RJIRPOWEANFUSNCZVDVZNMSFEKLOEPZLDKDJWSAAAAAAAOERHJCTNCKFRIMVKSOFOMKMANREWNBN RZUDRGXEEEEENFQIDVLQNCKNEEEEEDGLLLLLLAWIOSNCDARLODMTOEJXMILDFJROTKJSDNLVCZNN | |
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| Paarth Dave | Apr 30 2008, 07:15 AM Post #2 |
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Advanced Member
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What if the ADFGVX text is converted to alphabets by the given corresponding locations in the ciphertext? For example..let's take a random ADFGVX ciphertext. DFGFFAXFXFAAGDAAAFGVXGFV Now, if I convert DF into its location in the table and write its corresponding alphabet, then how will you identify if it is ADFGVX or not?? |
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Cryptography Vanquished.... | |
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| Revelation | Apr 30 2008, 09:38 AM Post #3 |
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Administrator
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You don't really, but then again it's not the classic ADFGVX cipher anymore, because you've added a step. |
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RRRREJMEEEEEPVKLWENFNVJKEEEEEAOLKAFKLXCFZAASDJXZTTTTTTTLSIOWJXMOKLAFJNNKFNXN RAGRBAQEMHIGDJVDSEOXVIYCELFHWLELJFIENXLRATALSJFSLCYTKLASJDKMHGOVOKAJDNMNUITN RRRRLJVEEEEECLYVYHNVPFTAEEEEEMWLMEIRNGLARWJAKJDFLWNTIERJMIPQWOTZEOCXKNUBNXCN RJIRPOWEANFUSNCZVDVZNMSFEKLOEPZLDKDJWSAAAAAAAOERHJCTNCKFRIMVKSOFOMKMANREWNBN RZUDRGXEEEEENFQIDVLQNCKNEEEEEDGLLLLLLAWIOSNCDARLODMTOEJXMILDFJROTKJSDNLVCZNN | |
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| s3c | Apr 30 2008, 02:00 PM Post #4 |
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Just registered
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that's a pretty good idea, normal way of breaking it sort of breaks down when doing this, how would you break something like that? |
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| Revelation | Apr 30 2008, 03:43 PM Post #5 |
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Well, we are having a discussion about that in this topic. |
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RRRREJMEEEEEPVKLWENFNVJKEEEEEAOLKAFKLXCFZAASDJXZTTTTTTTLSIOWJXMOKLAFJNNKFNXN RAGRBAQEMHIGDJVDSEOXVIYCELFHWLELJFIENXLRATALSJFSLCYTKLASJDKMHGOVOKAJDNMNUITN RRRRLJVEEEEECLYVYHNVPFTAEEEEEMWLMEIRNGLARWJAKJDFLWNTIERJMIPQWOTZEOCXKNUBNXCN RJIRPOWEANFUSNCZVDVZNMSFEKLOEPZLDKDJWSAAAAAAAOERHJCTNCKFRIMVKSOFOMKMANREWNBN RZUDRGXEEEEENFQIDVLQNCKNEEEEEDGLLLLLLAWIOSNCDARLODMTOEJXMILDFJROTKJSDNLVCZNN | |
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8:36 PM Nov 26
