Patent ID: 8312523

Claim:
A computer-implemented method for verifying authorization of Web service invocation requests based in part on generated digital signatures accompanying the requests, the method comprising: receiving a request from a requester to invoke an indicated single sign-on Web service on behalf of a user associated with the requester, the received request including a predefined identifier associated with the requester and a generated digital signature that is generated based at least in part on information included in the request and on other information that is not included in the request, the predefined identifier for the requester being associated with a predefined secret access key known to the requester; attempting, by one or more programmed computing systems of the single sign-on Web service, to verify that the request is from an authorized requester by generating a new digital signature for the request and by determining whether the new digital signature matches the digital signature included in the request, the generating of the new digital signature including retrieving the predefined secret access key that is associated with the predefined identifier included in the request and using the retrieved access key along with information included in the request for the generating of the new digital signature, such that the new and included digital signatures will match if the other information not included in the request that was used for generating the included digital signature is the retrieved predefined associated secret access key; and if it is verified that the request is from an authorized requester, initiating, by the one or more programmed computing systems, a customized sign-on process of the user with the indicated single sign-on Web service that includes providing to the user customized information specific to the requester, the customized information having been previously indicated by the requester.