Patent attributes
A client issues a first electronic request to access a service at a server. The server receives the request and identifies a type of challenge form among a number of different types of challenges (e.g., represented by a number of different XML schemas). The server issues a challenge, in accordance with the identified type of challenge, to the client. The challenge can include state information that indicates to the server when an appropriate response to the challenge is received. The client receives the challenge and formulates a response (including the state information) to the challenge in accordance with the identified type of challenge. The client issues a second electronic request, which includes the formulated response. The server receives the response and determines, based on the response, if the second electronic request is to be processed.
