Which of the following features will render a file unreadable without the proper cipher?

Compression reduces file size by removing redundant data, but it does not intentionally obscure the content to prevent unauthorized reading.

Encryption is the process of encoding information in such a way that only authorized parties can access it, making the file unreadable without the correct decryption key or cipher. It transforms plaintext into ciphertext using an algorithm.

Permissions control who can access or modify a file, but they do not make the file unreadable to an authorized user who has bypassed the permission system or been granted access.

A password is a form of authentication used to grant access, but it is not the process that renders a file unreadable; encryption is the underlying technology that uses a key to scramble data.