Authentication System and Method

Abstract

An authentication system for authenticating the identity of a requester of access by an unauthorized service client to a secured resource. The system has a messaging gateway having a first set of instructions operable to receive from a requester purporting to be an authorized user of a secured resource a request for limited access to the secured resource by an unauthorized service client for a particular transaction; a server having a second set of instructions operable to determine a key string known to both the secured resource and the authorized user the requestor purports to be, the key string being adapted to provide a basis for authenticating the identity of the requester as the authorized account holder; and a service user interface having a third set of instructions embodied in a computer readable medium operable to receive transaction specific information input into the request by the unauthorized service client.

I claim: 
     
         1 . A method for authenticating for authenticating the identity of a requester of access to a secured resource comprising the steps of:
 providing at least one interface adapted to receive and transmit data in communication with a user's application, a service client's application, or both;   receiving an authorization request message to authorize access to the secured resource by the service client, the authorization request message having been received through the at least one interface from the service client's application;   generating a challenge string with the challenge string being at least a partially random string having a plurality of symbols, wherein at least one of the symbols of the challenge string is a specially-designated symbol indicating the absence from said random string of a single randomly-selected symbol;   transmitting the challenge string though the user's application   receiving a response string corresponding to the challenge string, the response string having been received through the at least one interface from the user's application;   validating the service client's request to access the secured resource by determining if the response answers the challenge string.