Abstract: An isolated authentication device and related methods to provide a reliable means of authenticating the identity of its user to a network resource or server or other resource, and of authenticating the identity of a network resource or server or other resource to the device's user. The isolated authentication device may be attached to or in communication with a host device, such as a mobile telephone, personal digital or data assistant, GPS multifunction device, portable music player, wristband watch, personal computer, or similar device. A constrained operating system provides limited functionality, including authentication, data transfer, and cryptographic functions. Encrypted image, fingerprint, password, and/or personal identification number data is stored in read-only or protected nonvolatile memory. Input may be provided by means of a numeric or alphanumeric keypad, and images and information may be displayed on a screen. The device may be used to digitally sign a document, or a key to a lock.

Abstract: An isolated authentication device and related methods to provide a reliable means of authenticating the identity of its user to a network resource or server, and of authenticating the identity of a network resource or server to the device's user. The isolated authentication device may be attached to or in communication with a host device, such as a mobile telephone, personal digital or data assistant, GPS multifunction device, portable music player, wristband watch, personal computer, or similar device. A constrained operating system provides limited functionality, including authentication, data transfer, and cryptographic functions. Encrypted image, fingerprint, password, and/or personal identification number data is stored in read-only or protected nonvolatile memory. Input may be provided by means of a numeric or alphanumeric keypad, and images and information may be displayed on a screen.