Use Digital Signatures to Verify the Authenticity of an Image

Digital signature is dependent on the information signed, and thus its fundamental advantage over the handwritten signatures is the ability to detect the slightest changes in the information signed, invisible to the human eye.

Use GenerateDigitalSignature to sign an image you created or a photo you have taken with your digital PrivateKey. This will allow VerifyDigitalSignature to be used anytime later to make sure the image is an original and has not been altered by unauthorized or unknown means.

Generate a public-private key pair.

Get some bird images from the internet.

Create the digital signature for the first image.

Check the validity of the signature.

For comparison, check the signature for a different bird image.

Compare the image with its sharpened variant. The two images are difficult to distinguish visually.

However, because the underlying data has changed, verification of the sharpened image returns False, as expected.