What describes a file that has been encrypted for security purposes?

A file that has been encrypted for security purposes is best described as a hashed file. Hashing is a process that transforms data into a fixed-size string of characters, which is typically a series of numbers and letters. This process is primarily used for ensuring the integrity of the data, as it allows for original data to be verified and authenticated without revealing the actual content.

Encryption, while distinct from hashing in purpose and implementation, shares the objective of securing data from unauthorized access. When data is hashed, it generates a unique output based on the input data. If even a tiny change is made to the original data, the hash will change drastically, which is crucial for detecting alterations.

In the context of the options provided, although hashing and encryption are different, hashed files can be associated with security, especially when considering document integrity and verification. This makes the option of a hashed file the most relevant in describing a file secured through any means, aligning with the general theme of maintaining data protection and validation.