Linked Questions

4 votes
1 answer
3k views

Shortcuts / practicality of brute forcing block cipher (AES) + ECB with known plaintext [duplicate]

I know the plaintext (26 bytes long) and cryptotext of block cipher (suspected to be AES) in ECB mode. I can generate hundreds or thousands of such samples, but the samples are not arbitrary. What are ...
Konrads's user avatar
  • 165
0 votes
1 answer
1k views

Is it possible to obtain AES-128 key from a known ciphertext-plaintext-iv tuple used the encrypt the plaintext? [duplicate]

i have a file, which was encrypted with AES-128 in CBC mode. I know the content of original file and know the iv used to encrypt that file.So, just wondering if it's possible to recover the key used ...
user41449's user avatar
0 votes
1 answer
1k views

Is the key deducible with AES CTR when we know about the plaintext, IV and the ciphertext? [duplicate]

Simply as stated, with AES running in CTR mode, can somebody work out the key (without brute-forcing) given we know about the plaintext, IV and also the ciphertext. Assuming we also know about the ...
javaPhobic's user avatar
0 votes
0 answers
1k views

Aes brute force when part of data known [duplicate]

I have buffer of 16 bytes that encrypt with AES 128 cbc with IV =000000......(all IV is 0) I have the encrypted buffer, and I know 7 bytes from 16 bytes before the encryption , I dont know the key . ...
Keystone's user avatar
  • 101
1 vote
1 answer
267 views

Why can´t an attacker find the key if he has the plain text, the IV and the ciphertext? [duplicate]

I am reading a book about web security and they are now talking about AES CBC. After reading the chapter I was wondering, can an attacker compute my secret key if he has access to the IV, the plain ...
Daniel Oliveira's user avatar
0 votes
0 answers
440 views

Is it possible to recover the key to a decrypted file? [duplicate]

Is it possible to recover the key to a decrypted file if you have the initialization vector and it uses RijndaelManaged in CBC mode? If so how? The file I want to recover the key from is a xml that ...
lovemyencryptedxml's user avatar
2 votes
1 answer
302 views

Guessing the key in AES256-GCM? [duplicate]

I assume that my case is weird but I've the following information: IV: 0x263e or 0x3e26 Auth tag: 0x25 AES256-GCM encrypted payload: 0x4eec96df534ade4c013a AES256-GCM decrypted payload: ...
Guillaume's user avatar
-1 votes
1 answer
272 views

How dangerous is it to encrypt with AES 256 if the end user knows the unencrypted value? [duplicate]

I am implementing a bit of security in a system that was originally built without encryption on a specific piece of data. The plan was to encrypt this piece of data and include it as part of the ...
Crowcoder's user avatar
0 votes
0 answers
122 views

how many pairs of plaintext-ciphertext are needed before we break AES? [duplicate]

Imagine a set of words ($plaintext$) each are encrypted using AES-ECB mode and due to some leakage in the system an attacker could gain access to some pairs of $plaintext$ and $ciphertext$. But once ...
sashank's user avatar
  • 6,224
0 votes
0 answers
56 views

AES-XTS: find key from ciphertext and plaintext [duplicate]

Let's say I have a plaintext, the corresponding ciphertext encrypted using AES-XTS, and the initialization vectors. Is there any way - not brute force, of course - to compute the key? Even if there's ...
kiv's user avatar
  • 101
1 vote
0 answers
36 views

Is there a flaw in whole disk encryption vs volume or folder encryption? [duplicate]

My company just implemented whole disk encryption on all laptops (Symantec) and the concept seems flawed. Please correct me if I'm wrong, but if I have known file in plain text and that same file in ...
WombatPM's user avatar
  • 111
1 vote
0 answers
25 views

Is it possible to crack AES-256 ECB when provided with the ciphertext and a portion of the corresponding plaintext? [duplicate]

AES-ECB encrypts the message by breaking it into blocks and encrypting them one by one. Provided the knowledge of the ciphertext, a portion of the plaintext that corresponds to a block in the message, ...
Red Sun's user avatar
  • 342
6 votes
2 answers
2k views

Does having a known plaintext prefix weaken AES256? [duplicate]

I plan on storing data, encrypted with AES256, where the first dozen bytes are known plaintext. ('Hello World!' for example.) Does having this known plaintext prefix weaken AES256? I do not care ...
Matt Jones's user avatar
8 votes
2 answers
19k 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 ...
just.another.programmer's user avatar
2 votes
3 answers
5k views

Which attacks can be avoided by the use of OFB instead of ECB?

For a file encryption program, I was told to use Output Feedback mode (OFB) instead of ECB (Electronic code book) mode. Which attacks can I avoid by this choice?
goldroger's user avatar
  • 1,737

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