In a transposition cipher, what operation is performed on the letters of a message?

In a transposition cipher, what operation is performed on the letters of a message?

• A. Transposition Cipher
• B. Substitution Cipher
• C. Cryptography
• D. DDoS

Answer: (A)

Rearranging characters is the defining action in a transposition cipher. In this method, the letters of the plaintext stay the same, but their positions are permuted according to a rule or key. That’s why describing the operation as a transposition—that is, moving letters around—best fits the question. Substitution would replace each letter with a different one, changing the letter identities rather than just their order. Cryptography is the broader field, not a specific operation, and DDoS is a network attack unrelated to how ciphers transform text. For intuition, take HELLO and apply a simple permutation that swaps the first two letters: EHLLO. The letters themselves are unchanged, only their order is altered, which is exactly what a transposition cipher does.

Rearranging characters is the defining action in a transposition cipher. In this method, the letters of the plaintext stay the same, but their positions are permuted according to a rule or key. That’s why describing the operation as a transposition—that is, moving letters around—best fits the question. Substitution would replace each letter with a different one, changing the letter identities rather than just their order. Cryptography is the broader field, not a specific operation, and DDoS is a network attack unrelated to how ciphers transform text. For intuition, take HELLO and apply a simple permutation that swaps the first two letters: EHLLO. The letters themselves are unchanged, only their order is altered, which is exactly what a transposition cipher does.