Abstract: A photonic waveguide for conducting light having first and second wavelengths, the waveguide comprising superposed first and second strips of light conducting semiconductor materials having first and second refractive indexes, wherein the second wavelength is shorter than the first wavelength and the second refractive index is higher than the first refractive index, wherein the width and height of the first strip of light conducting semiconductor material are such that the first strip of light conducting semiconductor material is adapted to confine an optical mode of the first wavelength and the width and height of the second strip of light conducting semiconductor material are such that the second strip of light conducting semiconductor material is adapted to confine an optical mode of the second wavelength but is too narrow to confine an optical mode of the first wavelength.

Abstract: A controllable opto-electronic time stretcher comprising a first wave guide and a second waveguide coupled to the first waveguide along a coupling portion; wherein at least one of the first and second waveguides in the coupling portion has a controllable refractive index.

Abstract: A photonic waveguide for conducting light having first and second wavelengths, the waveguide comprising superposed first and second strips of light conducting semiconductor materials having first and second refractive indexes, wherein the second wavelength is shorter than the first wavelength and the second refractive index is higher than the first refractive index, wherein the width and height of the first strip of light conducting semiconductor material are such that the first strip of light conducting semiconductor material is adapted to confine an optical mode of the first wavelength and the width and height of the second strip of light conducting semiconductor material are such that the second strip of light conducting semiconductor material is adapted to confine an optical mode of the second wavelength but is too narrow to confine an optical mode of the first wavelength.

Abstract: A controllable opto-electronic time stretcher comprising a first wave guide and a second waveguide coupled to the first waveguide along a coupling portion; wherein at least one of the first and second waveguides in the coupling portion has a controllable refractive index.

Abstract: A system for creating non-repudiation (undeniable) watermarks, wherein a content provider uses outside distribution entities to distribute media content supplied by the content provider. Content watermarked by a distribution entity using this system is undeniably recognizable by the content provider as originating with that particular distribution entity. In other words, given N distribution entities, the content provider is able to tell which particular distribution entity watermarked the media content. The system does not allow any distribution entity to watermark media content so that would appear to have been watermarked by another distribution entity and the system does also not allow the content provider to watermark media content so that would appear to have been watermarked by a particular distribution entity. Consequently, this allows the content provider to place a high degree of trust in the identification of the distribution entity by means of the watermark.

Abstract: One embodiment of the present invention is a hybrid authentication system (10) for securing communication. In this embodiment, the system (10) includes a distributed authentication infrastructure (12) with a series of nodes (16) in communication with each other. These nodes (16) are intended to perform a series of functions, one of these functions being the authentication of other nodes. The system further includes a centralized authentication infrastructure (14), which is later integrated into the distributed authentication infrastructure (12) after the distributed authentication infrastructure (12) has been established. The centralized authentication infrastructure (14) includes a central server (22) coupled to the nodes (16) for verifying the identification of the nodes (16) and/or granting permission to those nodes (16).

Abstract: One embodiment of the present invention is a hybrid authentication system (10) for securing communication. In this embodiment, the system (10) includes a distributed authentication infrastructure (12) with a series of nodes (16) in communication with each other. These nodes (16) are intended to perform a series of functions, one of these functions being the authentication of other nodes. The system further includes a centralized authentication infrastructure (14), which is later integrated into the distributed authentication infrastructure (12) after the distributed authentication infrastructure (12) has been established. The centralized authentication infrastructure (14) includes a central server (22) coupled to the nodes (16) for verifying the identification of the nodes (16) and/or granting permission to those nodes (16).

Abstract: A system for creating non-repudiation (undeniable) watermarks, wherein a content provider uses outside distribution entities to distribute media content supplied by the content provider. Content watermarked by a distribution entity using this system is undeniably recognizable by the content provider as originating with that particular distribution entity. In other words, given N distribution entities, the content provider is able to tell which particular distribution entity watermarked the media content. The system does not allow any distribution entity to watermark media content so that would appear to have been watermarked by another distribution entity and the system does also not allow the content provider to watermark media content so that would appear to have been watermarked by a particular distribution entity. Consequently, this allows the content provider to place a high degree of trust in the identification of the distribution entity by means of the watermark.