Which of the following concepts describes the use of a one way transformation in order to validate the integrity of a program?

A hashing algorithm (such as MD5 or SHA-256) takes a program file as input and produces a fixed-length digest. Because hashing is a one-way function - meaning the original input cannot be derived from the output - it is used to create a baseline integrity fingerprint. If the program is later altered, recomputing the hash produces a different value, signaling tampering.

Key escrow is the process of storing cryptographic keys with a trusted third party for recovery purposes and does not involve one-way transformations for integrity validation.

Non-repudiation is a security property ensuring a party cannot deny an action and is not itself a one-way transformation used to validate file integrity.

Steganography hides data inside other files and does not produce a one-way mathematical transformation used to validate program integrity.