6  EP 1 499 940 B1 5  [0018] The present invention allows a reliable and ef- ficient identity management that can, with full interoper- ability, accommodate to various requirements of partici- pants,in particular the transferof authenticationand oth- er identity-related information, versionswhere a useronly has a browser or more powerful software, different loca- tion entities, also called wallets, holding informatio about theuser, andanonymousandidentifiedusers,and the integration of privacy policies. In other words, the invention enablesend usersof web-based services,e.g., e-business, to perform single sign-on and controlled ex- change of profile information with service providers. The invention works advantageously with standard HTTP (hypertexttransfer protocol) browsers, whichusuallypro- vide themain user interface.The presentedmethods and system support a zero footprint version, i.e., there is no other software needed, not even activecontent likeJava- script, Java, or ActiveX (Javascript and Java are trade- marks of Sun Microsystems, Inc., ActiveX is a trademark of Microsoft Corporation). Furthermore the invention al- lowsmultiple authorities,avoiding anysinglepoint of fail- ure. That also means that multiple authorities are sup- ported, giving users the chance to freely select among them, without the need to trust the others. Moreover, the authorities do not need totrust eachother unlikein known solutions like Passport or Kerberos. Kerberos is a net- work authentication protocol for providing authentication for client/server applications by using secret-key cryp- tography. [0019] In accordance with the present invention, there is presented a method according to claim 1. [0020] The method allows that the location entity is ei- ther remote or under local control of a person or user whose identity is concerned and also allows that the lo- cation of this person remains unknown to the requesting entity, which can be a server. This also holds when the identity-related information is transferred from the loca- tionentityeither(a) viathe clientapplication or (b)directly from the location entity with the location entity making the contact to the requesting entity. [0021] The acquiring step can redirecting sub-step for redirecting the location entity via theclient applicationtothe requesting entityand thereby transmitting the identity-related information to the re- questing entity. This has the advantage that it is faster than the above sub-steps, but can only safely be done for short identity-related information. [0022] It isadvantageousifthe transport protocolused between the requesting entity and the client application, aswell asbetween theclientapplicationand the location entity, is a secure hyper text transfer protocol (HTTPS), because then a secured transfer of information can be guaranteed. Using such a secure channel prevents so- called man in the middle attacks. [0023] The returned location information can be rela- tive to the location of the client application. The location information in the redirecting step denotes "localhost" if it is relative, and if it is absolute it may be a URL (uniform resource locator) or other information identifying the lo- cation entity from which the requesting entity derives a URL by a normal address translation locally or via a di- rectory. Information identifying a person concerned can also be used to derive by the requesting entity a URL of the appropriate location entity by a specific directory list- ing persons and their location entities. [0024] The redirecting step can be performed by a hy- per text transfer protocol redirect or short HTTP-redirect to localhost or the derived URL, transmitting to the loca- tionentity eitheranactualtransfer instruction and a return address or a contact address and possibly already the transfer instruction and return address. This enables the acquiring step with more flexible transport protocols and without requiring the client application, if it is a browser, to disturb the user for pushing a "submit" button to start a PUSH operation or to have scripting enabled. [0025] The method can further comprise accepting by the requesting entity the identity-related information to- gether with an authentication from the location entity un- der a location entity pseudonym, wherein the identity- related information corresponds to a personal pseudo- nym of a person. This has the advantage that anonymity of the personcan be protected reliably.Clearlythe meth- od also comprises normal, non-anonymous location en- tity identities and personal identities. [0026] The method can further comprise transmitting by the requesting entity a server policy for use of the identity-related information. In particular the requesting entity or server may include a promised privacy policy or privacy preference, e.g.Platformfor PrivacyPreferences (P3P), for the requested identity-related information, for example, in the transfer instruction by reference or di- rectly. Itmayalsoinclude another security- related policy, e.g., about secure storage. The identity- related informa- tionfromthelocation entity can alsocontain or reference aprescribedprivacy orothersecuritypolicy.Thishasthe advantage that the requesting entities can interact in op- timized ways with persons and location entities with dif- ferent policies, e.g., by then offering different degrees of personalization. The requesting entity is free to refuse continued the application-dependent interaction unless a minimum of information is provided. This may be indi- cated in the request, as well as other requirements on the information or its quality, such as confirmation by a certain class of authority,freshness,or liabilityof the con- firmer. [0027] The acquiring step can further comprise decid- ing by the location entity on what part of the identity- related information requested in the request step to be transferred on the basis of a predefined policy. This has theadvantage that the requesting entity canmake agen- eral request for all information that may be useful to it, but allow the location entity to decide, based on its own or the user’s policy, which of this information it actually wantsto offer, e.g., for marketing, personalization or sta- SUMMARY AND ADVANTAGES OF THE INVENTION 4