What does cryptanalysis aim to convert?

What does cryptanalysis aim to convert?

• A. Ciphertext to plaintext with the key
• B. Plaintext to ciphertext without the key
• C. Ciphertext to plaintext using a known algorithm
• D. Ciphertext to plaintext without knowing the key

Answer: (D)

Cryptanalysis is the practice of turning ciphertext back into readable text without having the secret key. The aim is to recover the plaintext without knowing the key by exploiting weaknesses in the cipher, patterns in the ciphertext, or other information that can reveal the original message. That’s why the option describing converting ciphertext to plaintext without knowing the key is the best fit. Using the key would be regular decryption, encryption is the opposite process, and simply applying a known algorithm doesn’t guarantee you can obtain plaintext without the key.

Cryptanalysis is the practice of turning ciphertext back into readable text without having the secret key. The aim is to recover the plaintext without knowing the key by exploiting weaknesses in the cipher, patterns in the ciphertext, or other information that can reveal the original message. That’s why the option describing converting ciphertext to plaintext without knowing the key is the best fit. Using the key would be regular decryption, encryption is the opposite process, and simply applying a known algorithm doesn’t guarantee you can obtain plaintext without the key.