Patent ID: 8533791

Claim:
A method, comprising: receiving a request to perform a second factor authentication from a first authentication server subsequent to a successful first factor authentication of a user computer by the first authentication server; and responsive to receiving the request, performing, by a second authentication server that is separate from the first authentication server, the second factor authentication of the user computer subsequent to the successful first factor authentication by the first authentication server, the second factor authentication comprising: outputting a challenge to the user computer, the challenge being a type of challenge selected by the first authentication server from a plurality of types of challenges that the second authentication server is configured to output, wherein outputting the challenge to the user computer comprises establishing a direct communication channel between the second authentication server and the user computer; receiving a response from the user computer to the challenge; and performing at least one of: responsive to determining the response from the user computer to the challenge is correct, outputting an indication to the first authentication server that the user computer passed the second factor authentication, or responsive to determining the response from the user computer to the challenge is incorrect, outputting an indication to the first authentication server that the user computer failed the second factor authentication.