What is Commit Signing?

Commit signing is a security method that adds a cryptographic signature to a code commit in a version control system like Git. This signature helps verify that the commit came from a trusted developer account and that no one altered the commit after signing. It helps prove that a code change is genuine and has not been tampered with. Platforms like GitHub support signed commits using GPG, SSH, or S/MIME, while GitLab supports signed commits and tags using methods such as SSH keys, GPG keys, and X.509 certificates.

Why Does Commit Signing Matter?

Git lets developers configure names and email addresses locally. Without signing, someone could make a commit that appears to come from another developer. Commit signing reduces this risk by linking the commit to a verified cryptographic key.

It also helps strengthen software supply chain security. When teams review code, merge changes, or audit commit history, signed commits provide stronger assurance that changes came from trusted contributors.

Code hosting platforms can also show a Verified label when they successfully validate a commit signature. GitLab, for example, verifies commit signatures and displays verification status for signed commits.

How Does Commit Signing Work?

Commit signing usually relies on a public and private key pair:

• Private key: The developer keeps this key secure and uses it to sign commits.
• Public key: The developer adds this key to the code hosting platform.
• Signature: Git creates a digital signature when the developer signs a commit.
• Verification: The platform checks the signature against the public key and confirms whether it matches the developer’s identity.

If the signature is valid, the commit can be marked as verified. If the signature fails, the platform may show it as unverified.

Common Signing Methods

Developers may sign commits using:

• GPG keys: A widely used method for signing commits and tags.
• SSH keys: Useful for teams already using SSH for Git authentication.
• S/MIME or X.509 certificates: Often used in enterprise environments.

The best method depends on the organization’s tooling, security requirements, and developer workflow.

What Commit Signing Does Not Do

Commit signing proves authenticity and integrity, but it does not prove that the code is secure. A signed commit can still contain bugs, vulnerable dependencies, exposed secrets, or insecure logic.

Therefore, teams should combine signed commits with code reviews, branch protection, code scanning, secret scanning, and dependency checks.

Supporting Trusted Development Workflows with Hexnode

Commit signing helps teams trust code changes inside the repository. However, secure development also depends on the devices developers use to write, sign, and push code.

Hexnode UEM helps organizations manage developer endpoints, enforce security policies, monitor compliance, and restrict risky device behavior. This supports a safer development workflow by helping ensure that code commits and access to repositories happen from managed, compliant devices.