A method for extending attributes (112, 113) in the memory of an ID token within a hierarchy of digitally coded trust settings by: - providing the ID token, wherein the ID token is equipped with a memory, an external interface, devices for authentication via the external interface and devices for read- and write-protected access to the memory via the external interface; - communicating, to a foreign attribute provider computer, a digitally coded trust setting for writing a foreign attribute to the memory of the ID token by an ID provider computer; - carrying out a cryptographic protocol for authenticating the ID token to the foreign attribute provider computer; and - verifying the digitally coded trust setting for writing the foreign attribute to the memory of the ID token and writing the foreign attribute to the memory of the ID token via the external interface thereof by the foreign attribute provider computer, further comprising the use of the foreign attribute for a transaction between a terminal computer connected to the ID token via the external interface thereof and a service computer with the steps of: - communicating, to the service computer, a digitally coded trust setting for reading the foreign attribute from the memory of the ID token by the ID provider computer; - requesting the transaction to the service computer by the terminal computer; - carrying out a cryptographic protocol via the external interface of the ID token to authenticate the ID token to the terminal computer and/or the service computer; - verifying the trust setting for reading the foreign attribute and reading the foreign attribute from the memory of the ID token via the external interface by the service computer; and - carrying out the requested transaction by the service computer. - providing the ID token, wherein the ID token is equipped with a memory, an external interface, devices for authentication via the external interface and devices for read- and write-protected access to the memory via the external interface; - communicating, to a foreign attribute provider computer, a digitally coded trust setting for writing a foreign attribute to the memory of the ID token by an ID provider computer; - carrying out a cryptographic protocol for authenticating the ID token to the foreign attribute provider computer; and - verifying the digitally coded trust setting for writing the foreign attribute to the memory of the ID token and writing the foreign attribute to the memory of the ID token via the external interface thereof by the foreign attribute provider computer, - communicating, to the service computer, a digitally coded trust setting for reading the foreign attribute from the memory of the ID token by the ID provider computer; - requesting the transaction to the service computer by the terminal computer; - carrying out a cryptographic protocol via the external interface of the ID token to authenticate the ID token to the terminal computer and/or the service computer; - verifying the trust setting for reading the foreign attribute and reading the foreign attribute from the memory of the ID token via the external interface by the service computer; and - carrying out the requested transaction by the service computer.