Identity medium

An identity medium is:


 * 1) "[a] device or object storing one or more credentials, claims, or attributes related to a single subject, and in the case of a device, capable of transforming these information objects for specific uses."
 * 2) "[a]ny credential, card, badge, USB, smart phone or other media, regardless of form factor, issued or authorized for identification purposes within online transactions.

Source
The White House, (Draft) National Strategy for Trusted Identities in Cyberspace: Creating Options for Enhanced Online Security and Privacy 33 (June 25, 2010).