Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [transposition-cipher]

A classical cipher in which the ciphertext is obtained by scrambling the letters of the plaintext.

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Shannon confusion and diffusion concept

I read the document(not the whole document) from Shannon where he speaks about the concepts of confusion and diffusion. I read in many places(not in the document but around the internet) that confusion is enforced using substitution. Diffusion is…
BrunoMCBraga
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About Cryptography in a Character Language

Suppose I had a message in Chinese (or another non-phonetic language) and I wanted to encipher it. Some of the simplest encryptions in English are substitution ciphers, but such ciphers don't seem to be a viable option for a language such as…
davidlowryduda
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How to solve cipher encrypted with Vigenère + Columnar Transposition?

Vigenère's weakness is Kasiski's test and index of coincidence. However, if you put columnar transposition on top of Vigenère, that weakness is gone. The text is now shuffled and you can't search for digrams/trigrams, because they will give you…
Pavancho Emiliano
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How to break a columnar transposition cipher?

I'm currently studying for a cryptography exam. I've been given ciphertext that has been encrypted by a columnar transposition cipher. I've been given no shift key length or key word, the only thing I know is that only 2 columns have been…
EMJ
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Obtaining the key length of a columnar transposition, given a known plaintext word

I'm revising for a cryptography exam at the moment and I'm having some problems with a question. The question looks for the key length of a cipher given that the word "earthquake" appears in the plaintext. Ciphertext: aaatr ksams itahb netrs weurs…
cian1500ww
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How to solve Columnar Transposition Cipher without a key

I have been given a 77 character message for decryption, but no matter where I look all the Columnar Transposition scripts out there are all requiring of a key. I believe the number of columns to be 7, but I am looking for a code that output all…
Rob
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Is this transposition cipher information-theoretically secure for 1 message?

Given: $m = \{0,1\}^{n}$; a plaintext message of length $n$ encoded in binary $k = randomshuffle([0, 1, ..., 2n-1])$; A secret key consisting out of unique numbers between 0 and $2n-1$ in a true random order. The key is only used once and preshared…
Daan Bakker
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Improve security of transposition ciphers

As we know, breaking a Transposition Cipher is quite trivial and can be easily done by either exploiting single letter frequencies (not $d$-gram frequencies though, given that $2 < d < L$), or by employing a simple CPA, thus deriving the snippets…
user3333434
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How secure is bit level permutation?

Could anyone explain how secure is bit level permutation? What is the most serious threat against the security of this kind of cipher?
Anna
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How to determine which type of transposition cipher I have?

I have some ciphertext that I have determined using frequency analysis to be most likely encrypted using a transposition cipher, as the letter frequencies are similar to plain English language text. I believe the next step should be to determine…
Lauren Hosking
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Are some combinations of Substitution + Transposition more vulnerable than others?

Iterating multiple substitution ciphers is not mathematically different from using a single substitution cipher (3 Vigenere iterations with a 31-, a 32-, and a 33-letter key would essentially be a single Vigenere cipher with a 32,736-letter key),…
Simpson17866
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Frequency analysis of transposition ciphers

Can we do frequency analysis of transposition ciphers? If yes, please tell me the procedure and I would be happy if you provide me with some links related to it. I heard that it can be done using bi-gram frequency. I did it for substitution…
Ali Mushtaq
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What is the post-quantum security of encryptions schemes based on transpositions?

I know that if using Grover's algorithm to break a cipher, one would need to perform (2^[key space])^0.5 queries (the square root of the number of all possible keys). A simple transposition cipher COULD have their security of (transpositions)!…
alpominth
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What is a block transposition cipher?

I was looking at the archives for the British national cipher challenge, and a modified version of an ADFGVX cipher came up twice (2003 2011), with block transposition instead of columnar transposition. The question I has is what is this referring…
Ra2orLeaf
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How to distinguish a transposition cipher from a simple substitution cipher only given a ciphertext?

I am working on one interesting question. There is a ciphertext that has 10,000 letters. We need to distingish whether this ciphertext was encrypted by a transposition cipher or a simple subsitution cipher. I understand a transposition cipher will…
董冠方
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