.0 Encryption

The fear of every surveillance society: citizens protecting their own privacy with strong cryptography

Re: .0 Encryption

Post by sidebottom on Sat Feb 28, 2009 1:28 pm
([msg=18888]see Re: .0 Encryption[/msg])

I don't know python and I just gave the encrypter a cursory glance but this "encryption" looks like just a simple mono-alphabetic substitution cipher. I don't want to be a downer, but if that is the case, with ample ciphertext it would be trivial to solve, even without the algorithm.
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Re: .0 Encryption

Post by TheMindRapist on Sat Feb 28, 2009 4:59 pm
([msg=18908]see Re: .0 Encryption[/msg])

sidebottom wrote:I don't know python and I just gave the encrypter a cursory glance but this "encryption" looks like just a simple mono-alphabetic substitution cipher. I don't want to be a downer, but if that is the case, with ample ciphertext it would be trivial to solve, even without the algorithm.

He's right, with unlimited data it is easy to see patterns, or make a program to find them for you.
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Re: .0 Encryption

Post by i_fallenhero on Mon Mar 02, 2009 8:56 pm
([msg=19118]see Re: .0 Encryption[/msg])

if there was unlimited data wouldnt it be harder to directly narrow down the pattern?
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Re: .0 Encryption

Post by sidebottom on Mon Mar 02, 2009 11:07 pm
([msg=19130]see Re: .0 Encryption[/msg])

No, with a larger sampling of ciphertext, you could create more accurate frequency analysis of the characters, bi-grams, tri-grams etc. This is especially useful the more you know about the plaintext (such as the language, length, etc.).

The thing is...no matter how complex a substitution cipher is, it's easily broken over time, especially with computers to assist.
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Re: .0 Encryption

Post by YayPython on Tue Mar 03, 2009 3:36 pm
([msg=19173]see Re: .0 Encryption[/msg])

sidebottom wrote:No, with a larger sampling of ciphertext, you could create more accurate frequency analysis of the characters, bi-grams, tri-grams etc. This is especially useful the more you know about the plaintext (such as the language, length, etc.).

The thing is...no matter how complex a substitution cipher is, it's easily broken over time, especially with computers to assist.

Good point. I'm designing the more complex cipher.

Hey, this was my first one.
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Re: .0 Encryption

Post by sidebottom on Wed Mar 04, 2009 10:05 pm
([msg=19288]see Re: .0 Encryption[/msg])

YayPython wrote:
sidebottom wrote:No, with a larger sampling of ciphertext, you could create more accurate frequency analysis of the characters, bi-grams, tri-grams etc. This is especially useful the more you know about the plaintext (such as the language, length, etc.).

The thing is...no matter how complex a substitution cipher is, it's easily broken over time, especially with computers to assist.

Good point. I'm designing the more complex cipher.

Hey, this was my first one.


No offense, but I am guessing you don't have any training in cryptography and really don't understand how good ciphers work. If this is not the case, disregard the rest of this post. Either way, happy coding!

If you're planning on doing a more complex substitution cipher you're not achieving any extra security. If you want to understand what makes a good symmetric cipher do some research on DES and AES. Try reading a book on Crypto like Cryptography and Network Security Principles and Practices by William Stallings (it's a pretty easy read) if you are really interested in the subject.
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Re: .0 Encryption

Post by YayPython on Sat Mar 07, 2009 5:20 pm
([msg=19510]see Re: .0 Encryption[/msg])

sidebottom wrote:
YayPython wrote:
sidebottom wrote:No, with a larger sampling of ciphertext, you could create more accurate frequency analysis of the characters, bi-grams, tri-grams etc. This is especially useful the more you know about the plaintext (such as the language, length, etc.).

The thing is...no matter how complex a substitution cipher is, it's easily broken over time, especially with computers to assist.

Good point. I'm designing the more complex cipher.

Hey, this was my first one.


No offense, but I am guessing you don't have any training in cryptography and really don't understand how good ciphers work. If this is not the case, disregard the rest of this post. Either way, happy coding!

If you're planning on doing a more complex substitution cipher you're not achieving any extra security. If you want to understand what makes a good symmetric cipher do some research on DES and AES. Try reading a book on Crypto like Cryptography and Network Security Principles and Practices by William Stallings (it's a pretty easy read) if you are really interested in the subject.

No, I don't have any real cryptography training. I will definatly read up on it to improve my work. Thanks for the advice!
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