The DevOps team has updated the application source code.

Hashing is the best control for detecting unauthorized changes to source code. By generating cryptographic hash values for approved versions of files, any modification—intentional or accidental—will result in a different hash, immediately indicating tampering.

Backups help recover data but do not prevent or detect unauthorized changes. File labels provide classification but do not ensure integrity. Security audits review compliance but do not continuously detect changes.

Hashing supports integrity assurance, which is a core security objective. Tools such as file integrity monitoring (FIM) systems rely on hashing to alert administrators when files are altered unexpectedly.

NIST and CIS controls emphasize hashing and integrity monitoring as essential for protecting code repositories, system files, and critical configurations, especially in DevOps and CI/CD environments.