There are different methods which are used to authenticate a document which contains a digital signature. Using a user name and password is one option, but is only provides a single level of security. If anyone discovers your user name and password, they can access the document and alter it. If using this method to digitally sign documents, it is wise to use two factor authentication, which requires a second level of authentication after the user name and password are entered.
Authenticating a Digital Signature Involves Two Processes
When you use a digital signature and encrypt it on your computer, this is only one step in the process making sure the document is authentic. After you send it to another person, they will need to be able to unencrypt the document to verify it is truly authentic. This is the second step in the process, which has to use the same method which was used to encrypt it on your computer. There are different options available, which include using digital certificates, public and private keys, two factor authentication, and tokens.