In embodiments, an authentication server interfaces between a user device with a self-signed certificate and a verifying computer that accepts a user name and password. The user device generates a self-signed certificate signed by a private key on the user device. The self-signed certificate is transmitted to a verifying party computer over a network. The verifying party stores the self-signed certificate with user identification data, including at least one of a user name, user address, user email, user phone number, user tax identification (ID), user social security number and user financial account number. In subsequent communications, the verifying party receives a certificate chain including the self-signed certificate, and matches that with the user identification data stored in a database.