The attacker knows at least one sample of both the plain text and the cipher text.

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Other than brute force, are there any attacks on Threefish-512 using only a single known plaintext block?

As per title, other than brute force, are there any attacks on Threefish-512 using only a single plaintext block? Are there any attacks like this in any other cipher?
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52 views

Avoiding known plaintext attacks with an additional XOR-Layer

Can a cipher that is vulnerable to an known plaintext attack be made secure by adding an additional XOR-encryption? That is: suppose I have an (w.l.o.g. symmetric) encryption algorithm E were the ...
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91 views

Known plaintext attack on 3 round SIMON block cipher

I am attempting to write a program to perform a linear approximation attack on a reduced round version of the SIMON block cipher, but I am stuck on how to actually apply the linear approximation to ...
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48 views

Encryption with a known plaintext

I'm building an application where users can be a part of groups, and can obtain and distribute URLs from the group page that allow anyone who clicks on them to join said group. Groups should not ...
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53 views

AES and Known-plaintext attack [duplicate]

Can you help me to finding some papers that shows AES is secure against known-plaintext attack?
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2answers
2k views

If I have the unencrypted text and the encrypted text, can I calculate the key?

If I have the unencrypted text and the encrypted text, can I calculate the key? It seems logical based on my limited knowledge of encryption that I should be able to... but it also seems like too ...
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54 views

Looking for encryption algorithm not subject to known-plaintext attack with IV reuse

I've encountered an interesting problem where we can basically say the following: We need to encrypt messages, but we have no room to store IVs. We can synthesize IVs; however an attacker would be ...
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94 views

Is the idea of a known plaintext attack really that new?

As you can probably guess, I just watched The Imitation Game, which hasn't really gotten points for historical accuracy... During World War II, Turing and his team fret that they can't know the ...
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103 views

Known-plaintext attack on two-dimensional affine cipher

Problem: We have a two-dimensional affine cipher with $n = 2,\,\,\,\mathcal{P} = \mathcal{C} = {\mathbb{F}_{16}^2}$, where $\mathcal{K} = \{ A,\,\,b\} $ and $b = (0,0)$. The encryption and decryption ...
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236 views

RC4 , Is it possible to find the key if we know the plaintext and ciphertext?

Is it possible to find the key if we know the plaintext and ciphertext with RC4. How should I write the algorithm?
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1answer
109 views

Keeping the key and IV safe when AES256 encrypting publicly known data

I am encrypting some publicly known data, and some private data using the same key, using AES256 with CBC. An attacker does not have the ability to choose what the public data is. Is this safe? (It ...
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1answer
80 views

Proving that an encryption scheme is susceptible to certain attacks

I'm currently trying to prove the following: Where p is a prime number of cryptographic size, prove that: e(m) = am + b (mod p) where a and b are private is open to a known plaintext attack e(m) = ...
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2answers
122 views

AES: Guess Password using the unencrypted text?

I am using the same password for some encrypted files currently (I know this is bad practice, though), and I wonder whether an attacker could decrypt if one decrypted file fell into his hands.
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449 views

Known plaintext attack on ElGamal encryption

Assume that Alice uses Bob’s ElGamal public key ( = 2, Yb = 8) to send two messages $M = 17$ and $M' = 37$ using the same random integer $k = 9$. Eve intercepts the ciphertext and somehow she finds ...
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1answer
58 views

What makes adaptive memory attack difficult for the adversary?

On page 11, definition 2 of "Simultaneous Hardcore Bits and Cryptography Against Memory Attacks", the paper outlines the following steps (PK,SK) public key and secret key are generated by defender ...
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33 views

Possible to determine the encryption key that was used by knowing the input and output of the encryption mechanism? [duplicate]

Assume that a malicious user knows what string is being encrypted (a user_id, for example, which the user can know) and can also see the result of the encryption (the encrypted user_id that is used to ...
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1answer
213 views

Blowfish ECB mode: Tools for known-plaintext attack?

I'm currently dealing with multiple blowfish-encrypted files that share the same key. All are encrypted using ECB mode judging from their appearance. I don't know what the key is but I know 64 byte ...
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0answers
73 views

Cryptodefense ransom use RSA-2048. Any chance with known plaintext attack? [duplicate]

The "new" kind of ransomware invade your computer and crypt all your files using the RSA-2048. Personally, I have been victim of cryptodefense: 40000 files encrypted... I'm not going to pay anything ...
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1answer
95 views

Meet in the middle attack - message and key

I clearly understand the story of Alice and Bob: Alice and Bob are going to use double DES. They know the keys K1 and K2. Alice sends to Bob the encrypted message c= EK1(EK2(m)). Bob decrypts the ...
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1answer
505 views

With HMAC, can an attacker recover the key, given many known plaintext/tag pairs?

Given many pairs of $(m, t)$, can the attacker compute the key $k$ satisfying $\text{HMAC}(k,m) = t$? (Assume that $k$ was chosen at random.)
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4answers
85 views

One time pad in CBC mode?

I have been searching about if it is more secure to use CBC mode in OTP but I can't find anywhere where people have sad that it is more secure. Question: Is CBC mode in OTP more secure? Because I ...
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1answer
71 views

function of crypt called “ICE” [closed]

Using exeinfo, I have identified a function of crypt called ICE. What is it? How can I find ...
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1answer
4k views

Decrypting encrypted files if i have the original files(Plain Text attack) [closed]

I have the following A Encrypted file and the same file in its original(not encrypted) form Now will it be possible to find the encryption/decryption key by comparing the the above two files are ...