Multiple choice general knowledge

Which mode of operation applies the block cipher to plaintext without XORing the plain text?

  1. CBC

  2. CFB

  3. ECB

  4. OFB
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C Correct answer
Explanation

ECB (Electronic Codebook) mode is the simplest block cipher mode where each plaintext block is encrypted independently without any chaining or feedback. The ciphertext is produced directly from the block cipher applied to the plaintext, with no XOR operation with previous blocks. CBC, CFB, and OFB all use XOR with previous ciphertext blocks or feedback in some way, making ECB the only mode that applies the cipher directly to plaintext.

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