Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [known-plaintext-attack]

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

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

In most cases this is recorded real communication.

If XOR cipher is used for example, this will reveal the key as plaintext xor ciphertext.

201 questions
2
votes
1 answer

How does one conduct a known-plaintext attack on an algorithm?

My question is two-fold: Say I am given a total black box and I have n number of plaintexts as inputs that map directly to $n$-number of ciphertexts as outputs. This is all I know, and I do not have access to the algorithm. Is it possible to…
the_endian
  • 165
  • 1
  • 7
1
vote
1 answer

Cipher recommendation for known-plaintext attack

I need to encrypt a 4-digit number. The cipher-text can be up to 11 digits long and there are no limits for the key size. Considering that the attacker has access to both the cipher-text and the plain-text but I want the key to remain secret, what…
Miguel
  • 13
  • 2
1
vote
1 answer

Is my XTEA encryption key safe if I publish my firmware both as plain text and encrypted?

I'm using this bootloader that implements XTEA encryption for uploading an encrypted firmware to small MCU: https://github.com/nyholku/diolan-plus2 the actual XTEA code is here: https://github.com/nyholku/diolan-plus2/blob/master/fw/xtea.asm It is…
nyholku
  • 13
  • 2
1
vote
0 answers

Encryption with both plaintext and ciphertext public

Does there exist a system wherein the encryption key/algorithm can be made indecipherable despite making arbitrarily many plaintext and ciphertext pairs available to the cracker? (Does this qualify as KPA attack security? ) If so, how strong is such…
Soham
  • 141
  • 2
0
votes
2 answers

Can an AES-256 key be generated for a large number of cribs?

I have a question in regards to Ransomware type viruses. I know that a number of these viruses use the AES-256 algorithm to encrypt user's files using a randomly generated key. I work in IT support and I had one client the other week who had lost a…
Olly Lennox
  • 1
0
votes
1 answer

Request for review: known plaintext mitigation by rotation and xor encoding

When using structured data inside a plaintext (such as gzip headers, xml, etc.) they generate known plaintext which may be useful in cracking the ciphertext. So I had these two ideas on how to make this known structure less useful to attackers while…
hildred
  • 101
  • 1
  • 1
  • 6
0
votes
1 answer

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 using Gen($1^n$). Adversary $A1$ generates $m_0$…
user1068636
  • 439
  • 2
  • 12
-5
votes
1 answer

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

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 there any known programs that can help me. any help…
Oodi
  • 11
  • 1
  • 1
  • 1