SHARED SECRET ARRANGEMENTS AND OPTICAL DATA TRANSFER
1 Assignment
0 Petitions
Accused Products
Abstract
Digital data is optically broadcast through an environment by controllably switching the brightness or chrominance of LED solid state lamps, or of other illumination sources (e.g., television screens and backlit computer displays). This optical data channel is useful to convey cryptographic key data by which devices within the environment can authenticate themselves to a secure network. In some embodiments, the optical modulation is sensed by the camera of a smartphone. The row data output by the smartphone'"'"'s camera sensor is processed to extract the modulated data signal. In some monochrome embodiments, data communication speeds far in excess of the camera'"'"'s frame rate (e.g., 30/second), or even the camera'"'"'s row rate (e.g., 14,400/second) are achieved. Still greater rates can be achieved by conveying different data in different chrominance channels. A great number of other features and arrangements are also detailed.
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Citations
30 Claims
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1-21. -21. (canceled)
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22. A method employing a smartphone camera pointed at a subject, the method comprising:
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setting a focus of the smartphone camera so the subject is unfocused; processing data captured by the camera to derive a cryptographic key; and engaging in a secure wireless transaction with a remote device, through use of said derived cryptographic key. - View Dependent Claims (23, 24)
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25. A smartphone comprising a camera, a processor and a memory, the memory containing software instructions operable to cause the smartphone to perform acts including:
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setting a focus of the smartphone camera so a subject is unfocused; processing data captured by the camera to derive a cryptographic key; and engaging in a secure wireless transaction with a remote device, through use of said derived cryptographic key. - View Dependent Claims (26, 27)
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28. A computer readable medium containing software instructions for configuring a camera-equipped smartphone to perform acts including:
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setting a focus of the smartphone camera so a subject is unfocused; processing data captured by the camera to derive a cryptographic key; and engaging in a secure wireless transaction with a remote device, through use of said derived cryptographic key. - View Dependent Claims (29, 30)
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Specification