A system performs digital notarization using a biometric identification service. A signature requesting service receives a request to validate a digital item with a signature for a person. The signature requesting service provides a payload that identifies the digital item and/or the person to an identity service. The identity service obtains one or more digital representations of biometrics for the person, determines an identity for the person, and returns a data structure including the payload and one or more identity attestations regarding the determined identity. The identity service encrypts at least a portion of the data structure using a private encryption key. A public encryption key for the identity service can then be used to decrypt the portion to verify that the data structure was generated by the identity service after determining the identity. In this way, validation can be verified to the full trust level of the identification service.