Minisign is a dead simple tool to sign files and verify signatures. It is portable, lightweight, and uses the highly secure Ed25519 public-key signature system. Signature files include an untrusted comment line that can be freely modified, even after signature creation. They also include a second comment line, that cannot be modified without the secret key. Trusted comments can be used to add instructions or application-specific metadata (intended file name, timestamps, resource identifiers, version numbers to prevent downgrade attacks).