I have a scenario where I do not have the key but I have plaintext 1, ciphertext 1, and ciphertext 2. Ciphertext 2 is built using the same key that was used to build ciphertext 1. Is there somehow a way to decrypt ciphertext 2 to get plaintext 2?

  • $\begingroup$ Blockciphers are KPA-secure. No luck. $\endgroup$
    – DannyNiu
    Oct 29, 2021 at 6:34
  • 3
    $\begingroup$ Does this answer your question? Is it possible to find the key for AES ECB if I have a list of plaintext and corresponding ciphertext? Note that if you have some CTF there might be some tricks like the number of blocks of C1 is way bigger than C2's and you may find similarities ( some block of C1 is equal to some block of C2) on the ciphertext blocks so that you may get some information about the P2. Still the encryption key is safe from you. $\endgroup$
    – kelalaka
    Oct 29, 2021 at 6:57


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