# Tag Info

Accepted

### How to determine which type of transposition cipher I have?

However how do I determine which transposition cipher I would need to use? Am I right to assume this is definitely a transposition cipher also? As you found out that the ciphertext has a similar ...
• 49.3k

### Shannon confusion and diffusion concept

I find the terms "confusion" and "diffusion" to be slightly nebulous and can lead to over-simplifications. Confusion For example, saying that "substitution" is responsible for "confusion" is not ...
• 19.8k
Accepted

### How to distinguish a transposition cipher from a simple substitution cipher only given a ciphertext?

Think about what properties of the plaintext are preserved by the candidate ciphers. You want to look for those patterns. Transposition moves letters around but keeps their identity. Substituting ...
• 1,042

### How to solve Columnar Transposition Cipher without a key

I wrote an answer to a related question earlier showing an example of how to break a columnar transposition cipher by hand. The basic steps are two-fold: Test different key lengths, and look for a ...
• 46.4k
Accepted

### What is the post-quantum security of encryptions schemes based on transpositions?

Grover's algorithm is an unstructured search algorithm that finds the input to a black box that results in a particular value. It doesn't matter how that black box is constructed, or what operations ...
• 15.4k
Accepted

### What is a block transposition cipher?

A block transposition is different from a block cipher such as AES or DES which are referred to be the wikipedia article to which you link. Instead, it is a rearrangement of the letters of a message ...
• 25.3k
Accepted

### what method of transposition does AES 256 encryption use

What method of transposition does AES use? Transposition is a simple movement of data to an alternative location. There are two relevant steps in AES when it comes to transposition: addRoundKey and ...
• 19.8k

### How secure is bit level permutation?

As a single transformation considered in isolation, a fixed bitwise permutation does not offer any security. If you examine the hamming weight (the quantity of '1' bits) of the data before and after a ...
• 19.8k

### How to distinguish a transposition cipher from a simple substitution cipher only given a ciphertext?

One method is to simply try and break it. If you get an answer by analyzing the ciphertext assuming it is from one method then you can disregard the other one, especially if you have a large ...
• 93.9k

### Can a message be encrypted with BOTH mono-alpha and poly-alpha ciphers?

I'm assuming that your Columnar Transposition Cipher (CTC) is as described as this site, since I found that the keyword ANNIE works. OTP First of all, the ...
• 49.3k

### How to glean info from a message that simply has the letters shuffled?

What you are describing is called a transposition cipher. First of all, it would be easy to detect which method you are using since the frequency distribution of your cipher text will be the same as ...
• 163

### What's the difference between permutation and transposition?

This answer focuses on bit permutations as used in the context of DES for bit permutations IP, IP-1, and E. It numbers bits starting from $1$, as in DES. A bit permutation is a function $g$ on the ...
• 144k

### How to determine which type of transposition cipher I have?

If the single character frequencies in your ciphertext indeed approximately match typical English letter frequencies — i.e. if the mix of letters is about 13% E, 9% T, 8% A, 7.5% O, 7% I, etc. — then ...
• 46.4k
1 vote

### Tranposition Ciphers

Your second Answer first. [2] write down the key column wise as shown ,then fill the plain text row by row so you will get the matrix of (len(plaintext)/7 x 7), now for ciphertext, take first row and ...
• 660
1 vote
Accepted

### Double permutation patterns for transposition ciphers, how to crack

While transposition ciphers may move bits around, they are entirely linear; and effectively perform substitution... except the data positions are substituted, instead of the values. Let's say I have ...
• 1,471
1 vote

### How to break an unknown ciphertext - transposition of some kind

If you know for sure that it is a transposition of some kind you can chek the average frequency with which the various letters appear in the natural language of the plain text and then compare them to ...
• 174
1 vote

### can a key be applied to half the cipher text

can a key be applied to half the cipher text Stream ciphers or Block Cipher with CTR mode can do so. how much time would it take to encrypt a 1.6 mb file with an average encryption algorthm. in ...
• 318
1 vote

### Acceptable condition for dictionary search

In a chosen plaintext attack, the expected ciphertext length required to conclude that a decryption is correct was derived by Claude Shannon and is called the unicity distance. It depends on the ...
• 23.1k
1 vote

### How to break a columnar transposition cipher?

(Although your question is for a long time ago) Transposition ciphers don't change the frequency of letters in their ciphertexts. So, you can implement a frequency attack. For decryption by this you ...
• 109
1 vote

### Frequency analysis of transposition ciphers

Sorry to burst your bubbles but i disagree, transposition ciphers are susceptible to frequency analysis. Transpotion ciphers only change their relative position not their individual symbols, thus ...
• 11

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