What is the method by which an electronic signature validates the signer's identity?

The method by which an electronic signature validates the signer's identity is by linking the signature to a digital certificate. A digital certificate acts as an electronic "identity card" that confirms the individual's identity and provides a means to verify the authenticity of the signature. When a person creates an electronic signature, it is generated using their private key, which is securely associated with their digital certificate. This ensures that the signature belongs to the individual specified in the certificate, and anyone with access to the corresponding public key can confidently verify that the signature was indeed created by the holder of the private key.

This process demonstrates not just identity validation but also integrity and non-repudiation, as the signer cannot later deny having signed the document. The strength of this method lies in the use of cryptographic principles and the trust placed in the digital certificates issued by trusted Certificate Authorities (CAs) within the PKI framework.