What is a Digital Signature?

A digital signature is a type of electronic signature, but not all electronic signatures are digital ones. Digital signatures use cryptography to verify their authenticity. Cryptography is a pretty complex topic in the information technology world and there are entire courses and even degree programs dedicated to the topic. Since this isn’t an information technology course we’re not going to get that deep, but it’s important to understand the basics to understand e-notarizations.

Digital signatures use a framework called Public Key Infrastructure (PKI). That sounds like a complicated information technology term, but the main idea is actually quite simple. Electronic certificates are issued in two parts: a public key and a private key. The private key is to be kept private by the certificate holder (the notary public, in this case) since that key is what is necessary to digitally sign a document. Anyone that possesses the private key can digitally sign a document.

When a document is signed using the private key a complex coded message is created. This is known as the digital signature. The program that creates the digital signature uses both the document and the private key. Since the original document is used as part of the digital signing process it means that the original document cannot be changed. If the original document is changed then it will not be valid when verified.

How is a document verified? That’s where the public key comes in. The public key is not kept secret and it uses the digital signature to verify that the document was signed by the private key. This ensures that the document was signed by the owner of the certificate and that the document was not altered. E-notarization helps to prevent forgery by both verifying the identity of the signer and the contents of the document.

But how does all of the technology work behind the scenes? That’s the topic for information technology courses. You can see California’s list of digital signature providers for Notary Publics here: http://www.sos.ca.gov/administration/regulations/current-regulations/technology/digital-signatures/approved-certification-authorities