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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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-...
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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 ...
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4k views

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 ...
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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. ...
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1answer
1k views

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 ...
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3answers
2k views

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 ...