# Questions tagged [hill-cipher]

The Hill cipher is a historic polygraphic substitution cipher invented by Lester S. Hill in 1929.

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### Block cipher linearity (in relation to hill ciphers)

So while I knew hill ciphers were a form of block cipher (I'm assuming all the ones I have solved to date were ECB or something similar), so that got me thinking. Is it possible to use hill ciphers in ...
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### Hill cipher. Any way around the not invertible matrices [duplicate]

Question: The plaintext JULY is encrypted using Hill Cipher with m = 2, to give the ciphertext DELW, then determine the encryption and decryption matrix My approach: We will form a 2x2 matrix of ...
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### Where can I find standardized implementations of lightweight cryptographic ciphers?

I am working on a project that requires encrypting messages with different ciphers. I am looking for the following ciphers: PRESENT, CLEFIA, LEA, Hill cipher, Affine cipher, Elliptic Curve ...
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### Figuring out key in hill cipher (chosen-plaintext attack)

I have been wondering what approach to take in order to figure out what key was used to encrypt a message using the hill cipher. I know it is possible to obtain it even if it were just a known-...
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### Are there ready-to-use software that can try many decryption techniques on a ciphertext, with no information?

Let's say I receive a 1 MB encrypted file, but I get no information about the encryption method, and no password. The only thing I can guess is that the person probably used a weak encryption method ...
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### Hill cipher — obtain matrix key [closed]

I have to solve Hill's cipher. I have only cipher text: CGQIYN and key: CFDG. I don't know how to decrypt it, because in all ...
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### Hill Cipher Plaintext Attack: Dealing with Non-uniqueness of Matrix Inverses?

I'm following along with my book. Here is an example of a plaintext attack from it: It is known that: plaintext = 'friday' ciphertext= 'pqcfku' $m$ = 2 We will use this to form the following matrix ...
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### Hill Cipher with unequal matrix

How can we encrypt a text in Hill Cipher with a key matrix that is 3x3 when the plaintext is even like "ATTACKS"? Do we need to add padding like "x" or "z" to make the matrix equal? Thanks.
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### Security of the iterated Hill Cipher

I can understand that the basic Hill Cipher is susceptible to known plaintext attacks, but suppose the Hill Cipher is modified into the Iterated Hill Cipher. For a plaintext $x_0=m_0$ and an ...
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### How can I decode a Hill Cipher without a key? [duplicate]

On my exam, we had to solve this problem: message matrix is: [20, 19, 14; 17, 0 10] and the ciphertext matrix is: ...
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### hill cipher encryption way 1x3 plaintext matrix

Can someone help me with a Hill cipher? When do I have to use: 1x3 plain text matrix (p1, p2, p3) * 3x3 key matrix 3x3 key matrix * 3x1 plain text matrix Or they are both correct? I tried to ...
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### Hill cipher cryptanalysis - known plaintext known key size

Hello I want to know how to go about this problem I know the plaintext "abcdef" and the ciphertext. The key size is 2. I really can't figure out how to find the key for decrypting and encrypting.
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### Calculating the inverse modularity of the determinant for Hill cipher

I'm trying to decrypt a message encrypted with Hill Cipher, but I don't understand how to find the determinant so it solves the equation $det * 1/det = 1 mod 26$. The determinant for my key matrix is ...
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### Hill cipher, unknown letter value

I've been struggling on this problem for a while now : the Hill cipher is well-known to be vulnerable to known-plaintext attack due to its linearity. Given a key matrix $K$ of size $n\times n$, one ...
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### Are there any hand ciphers not obsoleted by computer cryptanalysis? [duplicate]

Computerized cryptanalysis has obviously made formerly "secure" hand ciphers like Playfair, Four Square, and the Hill Cipher obsolete because they can be defeated in seconds. But is there a hand ...
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### Hill Cipher - Unknown plaintext attack, known key [duplicate]

I was wondering if I have the key and the encrypted Hill Cipher message(s). I can definitely figure out the charset involved. But the order is missing. Assuming that I use 37 modulo or higher. How ...
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### Hill-cipher, disordered alphabet

I am going to apply a simple substitution cipher to my input, then encrypt the result with a Hill cipher. How can this be broken, in a chosen-plaintext threat model? In other words, instead of the ...