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CodesInChaos
CodesInChaos
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Tweeted twitter.com/#!/StackCrypto/status/487379826907811840
Added example from the comments into the question text, as it made it into several answers.
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e-sushi
e-sushi
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I was watching a Stanford lecture on Vigenère cipher and in it the professor said that – to break the cipher – we assume the length of the key is known. We then break the cipher into groups of this known length and then pick up (successively) the first, second, etc. members of each group and then break each of these using Caesar cipher.

The problem is: how would one break the cipher if the message length is short? Because then, we can not use the method which utilizes the frequency of letters to break the code.

For example:
Given the ciphertext ZZZJUCLUDTUNWGCQS and key is of size 6, can you crack this?
(Assuming you don’t know that the plaintext is WHATANICEDAYTODAY and the key is crypto.)

I was watching a Stanford lecture on Vigenère cipher and in it the professor said that – to break the cipher – we assume the length of the key is known. We then break the cipher into groups of this known length and then pick up (successively) the first, second, etc. members of each group and then break each of these using Caesar cipher.

The problem is: how would one break the cipher if the message length is short? Because then, we can not use the method which utilizes the frequency of letters to break the code.

I was watching a Stanford lecture on Vigenère cipher and in it the professor said that – to break the cipher – we assume the length of the key is known. We then break the cipher into groups of this known length and then pick up (successively) the first, second, etc. members of each group and then break each of these using Caesar cipher.

The problem is: how would one break the cipher if the message length is short? Because then, we can not use the method which utilizes the frequency of letters to break the code.

For example:
Given the ciphertext ZZZJUCLUDTUNWGCQS and key is of size 6, can you crack this?
(Assuming you don’t know that the plaintext is WHATANICEDAYTODAY and the key is crypto.)

Poor Mr. Vigenère… they never get his name right. Fixed the rest of the typos while I was at it and replaced the “cipher“ with the “classical-cipher” tag.
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e-sushi
e-sushi
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How can a vigenereVigenère cipher be broken if the message is short?

I was watching a stanfordStanford lecture on vigener cipherVigenère cipher and in it the professor said that – to break the cipher – we assume the length of the key is known.We We then break the cipher into groups of this known length and then pick up (successively) the first,second second, etc. members of each group and then break each of these using casesar cipherCaesar cipher.The

The problem is: how would beone break the cipher if the message length is short because? Because then, we cannotcan not use the method which utilisesutilizes the frequency of letters to break the code.

How can a vigenere cipher be broken if the message is short?

I was watching a stanford lecture on vigener cipher and in it the professor said that to break the cipher we assume the length of the key is known.We then break the cipher into groups of this known length and then pick up (successively) the first,second etc members of each group and then break each of these using casesar cipher.The problem is how would be break the cipher if the message length is short because then we cannot use the method which utilises frequency of letters to break the code.

How can a Vigenère cipher be broken if the message is short?

I was watching a Stanford lecture on Vigenère cipher and in it the professor said that – to break the cipher – we assume the length of the key is known. We then break the cipher into groups of this known length and then pick up (successively) the first, second, etc. members of each group and then break each of these using Caesar cipher.

The problem is: how would one break the cipher if the message length is short? Because then, we can not use the method which utilizes the frequency of letters to break the code.

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user3676846
user3676846
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