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Motification Of Otp Using Chaocipher

meghaditya
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meghaditya
Just registered
Joined: May 9th, 2011, 6:44 pm

May 17th, 2011, 12:56 pm #1

Hi guys
I am doing bachelors in CSE from Jadavpur University,Kolkata,India.
I have recently become very much interested in Cryptography, especially i found the one time pads fascinating.
I have tht abt an idea to achieve the Shannon's Perfect Security Concept of OTP by adding an extra cipher to the system.The description of the system is as follows, please comment if u hav any sugg regarding the system(MOTPEX)
The main problem with OTP is key maintenance and random key generation(also to some extent the one-time-usability of the key), so I decided to remove that constraint by adding an extra layer of encryption. It follows the Chaotic Permutation Cipher(courtesy Moshe Rubin and John Byrne) which itself is one the most difficult classical ciphers to break.
So the sender generates a master key which is at least as long as the message itself, and then encrypts the key by using that chaocipher. the encrypted key is then used to encrypt the message as per OTP.
The receiver similarly encrypts the received master key(as it must be shared between the two parties) and encrypts it to decrypt the cipher text using OTP algo.
Thus the security measures regarding the key is slightly relaxed.
Please give suggestions abt the proposition.
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kryptosfan
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kryptosfan
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Joined: September 4th, 2011, 6:09 am

September 17th, 2011, 6:03 am #2

Since the method for chaocipher is known, all you would have to do is break the chaociphered master key.

It seems like this uses the same math as OTP but not the same principles. I can't quite put my finger on it but it just doesn't seem to be the equivalent of a one time pad. It's a little late where I am though so maybe the ole noggin' is just shutting down. Could someone else explain the disparity? It's just mod addition with an encrypted key, right?

Implementation of this would be a little challenging especially from the posts saying that chaocipher is error prone and unintelligible after those errors.
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