Abstract: Methods and device for digitally signing documents by using a portable device that encodes a signature string to sound. The acoustic signature string may be transmitted and then decoded back into digital data. The signature string may be further processed to verify the signature of the document and to produce a certificate of identity and integrity for the document. The certificate of identity and integrity may be used to further identify and validate the document and its signer.

Abstract: Methods for the secure identification of the owner of a portable device by a service provider, wherein the portable device may be in communication with the service provider over a voice line such as a telephone line or the like, and the portable device does not require a personal computer. Furthermore, the methods provide for one-way, non-repudiable, non-trackable identification of the owner of a portable device, and for the arbitration of a disputed transaction between the owner of a portable device and a service provider.

Abstract: Methods and device for digitally signing documents (140) by using a portable device (110) that encodes a signature string to sound. The acoustic signature string may be transmitted and then decoded (150) back into digital data. The signature string may be further processed to verify the signature of the document and to produce a certificate of identity and integrity for the document. The certificate of identity and integrity may be used to further identify and validate the document and its signer.

Abstract: Methods for identifying a remote user of a portable device by using the portable device to encode sound corresponding to the identification of the remote user. The sound is received by a microphone external to the portable device and converted to an electrical signal. The electrical signal is transmitted to a processing device, that may be remote to the microphone, where the electrical signal is processed and the identification of the remote user is completed.

Abstract: A method of generation and detection of acoustic signals carrying alpha-numeric data for reducing the effects of noise and thereby improving signal transmission without the need to boost the power of the signal. In accordance with one aspect of the invention, a special DTMF acoustic signal consisting of a combination of two frequencies will be generated for the representation of a particular alpha-numeric character that will be similar to the standard DTMF tone. The difference between the amplitudes of both frequencies varies during the time of generation of the DTMF tone in such a way that both signals will arrive at a final destination detector, i.e., an interactive voice response board, at least for a portion of the generation time, at a relatively similar amplitude, thereby substantially increasing the probabilities of being recognized as a DTMF signal.

Abstract: A container is disposed within a vacuum insulation jacket which surrounds a vessel or pipe which contains or through which flows a hydrogen containing medium. The container holds oxygen under pressure or holds a material which liberates oxygen when exposed to heat and/or reacts with water to liberate oxygen. The container is sealed by means of a membrane of palladium or palladium alloy. A water absorbing material is disposed inside the container. The palladium membrane is thus exposed on its first side facing the interior of the container to a region of relatively high oxygen pressure produced by the oxygen inside the container and low hydrogen partial pressure inside the container, and is exposed on its other side to the vacuum (low oxygen pressure, and higher hydrogen partial pressure as a result of the outgassing or permeation of hydrogen from the medium in contact with the vacuum chamber walls).

Abstract: The invention provides a hydrogen pump for vacuum insulation jackets for a vessel or a pipe which holds or through which flows a hydrogen-containing medium at temperatures such that hydrogen permeates into the jacket, comprising a palladium or palladium alloy membrane exposed on one side to an oxidizing atmosphere and on its other side to the evacuated space within the jacket, wherein the membrane enables the flow of the hydrogen from the evacuated space through the membrane into the oxidizing atmosphere.