A method is provided for validating an assertion provided by a web resource. The method includes: sending a first request to the web resource over a communications network; responsive to the first request, receiving a web page from the web resource, the web page including at least one user-selectable representation of a cryptographic credential, the cryptographic credential including at least one assertion that is based on underlying data and at least one proof that allows verification that the assertion accurately reflects the underlying data without revealing the underlying data; receiving a selection of the user-selectable representation that causes a second request for verification of the proof to be sent over the communications network; and responsive to the second request, receiving a response indicating whether or not the representation accurately reflects the underlying data.