Eve has tricked Alice into decrypting a bunch of ciphertexts that Alice encrypted last month but forgot about. What type of attack is Eve employing?

Eve is employing a chosen-ciphertext attack.

Explanation:

Encryption is a strategy employed in the cyber world to allow sensitive and private data to be unreadable in the form of text or make the content of the data inaccessible by intruders. This is imperative to guard data and can only be accessed with the use of a key (password). Whoever has the authorized key could get access to the data thereby making the encrypted data readable in the process called Decryption.

The Ciphertext is a term used to explain data encrypted in the form of text.

When Eve tricked Alice into decrypting a bunch of ciphertexts, she was interested in having the general public key or private key depending on what she wants to get access to which makes it a chosen-ciphertext attack. Usually, these keys are in algorithm formats with long characters. When the chosen-ciphertext is analyzed by Eve, then she could guess the user secret key.