Questions tagged [known-plaintext-attack]

KPA is a form of cryptanalysis where the attacker can compare plaintext massages with the resulting ciphertext in order to find statistical weaknesses in the cipher or determine the private key. KPA resistance is a considered a must-have property for any modern cipher.

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Microsoft exchange server data breach relevance to IND-CPA, IND-CCA1, IND-CCA2

I was studying about the Microsoft exchange server data breach attack of 2021 as part of assignment case study. One of the tasks of the assignment it to find its relevance with IND-CPA, IND-CCA1, IND-...
Rohan Padshah's user avatar
1 vote
1 answer

Guess encryption algo and parameters from pair of raw/encrypted text

I have a several tuples of raw and encrypted text from a blackbox service. What would be the most reasonable approach to guess/bruteforce the encryption algorithm and parameters (IV, key) that are ...
Sultan Omurzakov's user avatar
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2 answers

Is possible to reverse engineer a AES encryption of a known file format?

If the encrypted file is from one of the known formats, such as doc, jpg, mp3, etc., is it possible to reverse engineer it and decrypt it? I "roughly" know the mechanic behind the AES ...
Noob001's user avatar
1 vote
1 answer

Can I get AES CBC key from known plaintext, ciphertext, iv? [duplicate]

Long story short: I was using AES CBC PKCS5 on my image server, but I lost my keys (one key per image). I know the first 61 bytes (the original and the encrypted) of each image plus I know the IV, and ...
Mk Domain's user avatar
1 vote
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Partial plaintext with pkcrack

First off, I know very little about cryptography, as I am sure my post below makes clear. The short version is I presume I need to use the -o (offset) function of pkcrack, but I'm not sure how to work ...
pkcrack-help's user avatar
1 vote
1 answer

Will using CTR mode with unique IVs, but only one password for encrypting multiple files, leak data or keys?

I'm working on a project to encrypt many files with a single password. The steps I will employ to encrypt the files are: user will execute a command similar to tool --encrypt --recurse directories/...
Raz Varren's user avatar
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2 answers

Is it safe to encrypt some data which contains a uuid while also sending the uuid as metadata?

I have a json data-interchange format where I send messages like the following: { "revision": { "client": "f0ede1da-7314-4e59-99f7-a3a71dcab11f", patch: ["hello world", 0] }, "client": "f0ede1da-...
brainkim's user avatar
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Close Port 587 - Ramifications?

Our recent PCI scan failed because "Plaintext authentication is allowed over unencrypted channel on SMTP." As such, our tech support suggested to close port 587. What are the effects of closing port ...
Arvy S.'s user avatar
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4 votes
1 answer

Security of AES against known plaintext attack if no IV is used?

I understand the the statement that "AES is not currently vulnerable to known-plaintext attack" but I assume that there is an implicit rider in that statement that should be read "when used in an ...
user2195559's user avatar
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Do known plaintext attacks lead to exposure of the key?

I say that if a professional code breaker has a bunch of data, the encoded version of said data and the encoding method he can figure out the encoding key. It is just a matter of having enough data. ...
user39566's user avatar
2 votes
1 answer

Reversing a block hash of SHA-1 with known Plaintext?

Is it possible to reverse the hashing of a block in a Datastream fed to an SHA1 if the plaintext for that block is known? If it is not possible (which I assume) does it make attacks to retrieve the ...
Patrick Huy's user avatar
1 vote
3 answers

Is symmetric encryption vulnerable to known plaintext attack?

If Bob sends some plaintext to Alice for encryption before sending the ciphertext to Carol, can Bob deduce the key by comparing the plaintext and ciphertext assuming only Alice and Carol knows the key ...
John's user avatar
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