Multi-party, secure multi-channel authentication

A method of providing an unregistered user access to a resource that requires an indication of approval by an authenticated user who is registered to the resource, the method comprising:

• receiving, by an authentication system, a request from the unregistered user to access the resource during a user session and user session information, wherein the request and the user session information are transmitted over a first channel;
• creating, by the authentication system, a session record including the user session information and a token value for the user session;
• transmitting, by the authentication system, the token value to the unregistered user over the first channel;
• receiving, by the authentication system, the token value from the authenticated user over a second channel, wherein the token value and the user session information are provided to the authenticated user by the unregistered user;
• displaying, by the authentication system, the user session information to the authenticated user, wherein the user session information is retrieved from the session record by the authentication system based on the token value;
• receiving, by the authentication system, verification from the authenticated user that the user session information displayed matches the user session information provided to the authenticated user by the unregistered user;
• receiving, by the authentication system, the resource selected by the authenticated user along with the indication of approval to allow the unregistered user to access the resource;
• and
• upgrading, by the authentication system, the user session to indicate that the unregistered user is granted access to the resource.