Abstract: A device comprising: an input for receiving a signal from a rolling-shutter camera which captures frames by exposing a lines of each frame in sequence, the signal comprising a coded light signal; and a signal processing module arranged to obtain a respective sample of the coded light signal from each of a number of said lines, being a substantially smaller number of the lines than exposed by the camera in each frame. The coded light signal comprises a message having a duration longer than this number of lines, and the message is repeated multiple times with a timing such that a different part of the message is seen by the camera in each of a plurality of different ones of said frames. The signal processing module is configured to time align the different parts of the message from the plurality of different frames, and reassemble the message from the time-aligned parts.

Abstract: A Wiener filter for equalizing an effect of a first filter on an input signal which is subject to the first filter and to noise and/or interference, wherein: the first filter is dependent on at least one unknown quantity; and the Wiener filter is configured based on an averaged representation of the first filter averaged over the at least one unknown quantity, in place of a representation of the first filter being assumed to be known.

Abstract: A transmitting device comprises a transmitter, and a controller for receiving transmission requests from a request source. The controller comprises a queue, and is configured to queue the transmission requests in order from the front of the queue backwards, and to enact the transmission request at the front of the queue by controlling the transmitter to perform the transmission of the corresponding message. The controller is further configured to detect that at least one of these transmission requests is to be treated as a repeating request, and in response, to re-insert the repeating request in the queue in one of the places farther back than the front after transmission of the corresponding message, so as to retransmit the corresponding message at least once.

Abstract: A cryptographic system (100) is provided for distributing certificates comprising a certificate authority device (110) and multiple network nodes (140, 150, 160). A network node (140) sends a public key to the certificate authority device. The certificate authority device (110) generate a certificate comprising the public key, forms an identifier by applying an identity forming function to the certificate and generates local key material specific for the network node by applying a local key material generation algorithm of an identity based key pre-distribution scheme on the identifier, and sends the local key material encrypted to the network node. The network node may be authenticated implicitly through its access to a shared key obtainable from the local key material.

Abstract: A cryptographic device (200) is provided to compute a key dependent cryptographic function for an input message. The cryptographic device has a data store arranged to store multiple variables (w) on which the cryptographic device acts to compute the cryptographic function, a variable (w) being distributed over multiple shares (wj) and represented in the data store as multiple encoded shares (xj), an encoded share being an encoding (xj=Encj (wj, sj)) of a share (wj) together with a state (sj), the multiple states (sj) corresponding to the same variable (w) having a relationship with the input message (M) so that there exists an injective mapping (?) from the input message (M) to the multiple states (?(M)=(s0, . . . , sn?1)).

Abstract: A cryptographic device (100) arranged to compute a target block cipher (Bt) on an input message (110), the device comprising a first and second block cipher unit (121, 122) arranged to compute the target block cipher (Bt) on the input message, and a first control unit (130) arranged to take the first block cipher result and the second block cipher result as input, and to produces the first block cipher result only if the block cipher results are equal.

Abstract: A cryptographic device (100) for calculating a block cipher (500) on a block cipher input (105) and producing a block cipher output (106), the block cipher calculation operating on encoded values (210), the cryptographic device comprising a round function unit (140; 300) for applying the final round (118) of the multiple rounds of cryptographic processing implementing the block cipher, a first output unit (160) and second output unit (180) for decoding encoded output data (132, 152).

Abstract: A transmitting device comprises a transmitter, and a controller for receiving transmission requests from a request source. The controller comprises a queue, and is configured to queue the transmission requests in order from the front of the queue backwards, and to enact the transmission request at the front of the queue by controlling the transmitter to perform the transmission of the corresponding message. The controller is further configured to detect that at least one of these transmission requests is to be treated as a repeating request, and in response, to re-insert the repeating request in the queue in one of the places farther back than the front after transmission of the corresponding message, so as to retransmit the corresponding message at least once.

Abstract: A coded light signal is embedded into visible light emitted from the light source, to be received by a rolling-shutter camera which captures frames (16) by exposing a plurality of lines (18, 24) of each frame in sequence, the camera having an exposure time with each line being exposed for the exposure time. The coded light signal is formatted according to a format whereby the coded light signal comprises at least one message and the message is repeated multiple times with a timing such that, when samples of the coded light signal are obtained from a substantially smaller number of lines (24) than exposed by the camera in each frame and the message is longer than this number of lines, a different part of the message is seen by the camera in each of a plurality of different ones said frames.

Abstract: An initiating key-agreement device (100) and a responding key-agreement device (200) are provided, configured to generate a symmetric key shared between them. The devices are configured for generating in electronic form a private random value (112, 212), obtaining in electronic form a public set of bivariate polynomials (122) and computing a univariate polynomial (124, 222) by summing the univariate polynomials obtained by substituting the private random value (112, 212) into the polynomials of the public set (122). The devices are configured to send their computed univariate polynomial to the other device, and to compute or reconstruct the shared symmetric key (214, 312) by substituting its generated private random value (112, 212) in the received univariate polynomial.

Abstract: The invention provides a communication system (500), a lighting system, a method of transmitting information and a computer program product. The communication system according to the invention is configured for transmitting data via visible light. The communication system comprises a signal generator (530) for generating a light driving signal (200) being a frequency shift key modulated signal comprising a sequence of signal parts (215, 225), each signal part being modulated at a first or second frequency in accordance with the data, the signal parts modulated at the first frequency having first pulses in first periods (T0) and the signal parts modulated at the second frequency having second pulses in second periods (T1). Energy of the visible light corresponding to a pulse in a respective period has center of gravity in time.

Abstract: A key generation device (100) configured to generate a public key (126) for use in a public key encryption device and a corresponding private key (114) for use in a private key decryption device, the key generation device comprising a private key generator (110) configured for obtaining in electronic form a private random value (112, s), and generating the private key (114), the private key comprising the private random value (112), and a public key generator (120) configured for obtaining in electronic form a public set of bivariate polynomials (122, fi(,)), computing a public univariate polynomial (124) by summing over univariate polynomials obtained by substituting the private random value (112, s) into the polynomials of the public set (122, fi (s,)), and generating the public key (126), the public key comprising the public univariate polynomial (124) and the public set (122).

Abstract: The invention relates to the field of IEEE 802.15.4 based networks, and in particular to methods and devices for transmitting and receiving messages in IEEE 802.15.4 based networks. The existing IEEE 802.15.4 standard is further improved and adapted to better fit the properties of a network of lighting devices. The improvements and adaptations of the existing IEEE 802.15.4 standard allow for more flexible addressing. Bits which are indicative of use of address fields and/or whether one or two frame control fields is/are present in the ordered data portions of the message to be transmitted are defined by the device transmitting the message in the IEEE 802.15.4 based network. Existing features of the existing IEEE 802.15.4 standard protocol are retained.

Abstract: There is provided a light detection system which is capable of determining in light embedded codes by detecting light in a scene which is illuminated by an illumination system (110) comprising one or more light sources (111,112,113) each providing a light contribution (I111, I112, I113) comprising an embedded code (ID#1, ID#2, ID#3) emitted as a temporal sequence of modulations in a characteristics of the light emitted. The light detection system comprises light detection means (220), which are arranged for acquiring at least one image of the scene, where the image is acquired a plurality of temporal shifted line instances. Each line of the acquired image comprises an instance of the temporal sequence of modulations of the first embedded code. The light detection system further comprises means (230) for determining embedded codes from the spatial pattern of modulations.

Abstract: A cryptographic system is provided comprising multiple configuration servers (200, 201, 202) arranged to configure multiple network devices (300, 350, 360) for key sharing. Each configuration server comprising a computation unit (220) arranged to compute local key material for the network device from root key material specific to the configuration server and the network device identity number of the network device that is being configured. At least two configuration servers of the multiple configuration servers provide computed local key material to said network device. The network devices are configured to determine a shared key with any one of multiple network devices. A network device comprises a shared key unit (330) arranged to derive a shared key from another network device's identity number and at least two of the multiple local key materials of the network device.

Abstract: A key generation device (100) configured to generate a public key (126) for use in a public key encryption device and a corresponding private key (114) for use in a private key decryption device, the key generation device comprising a private key generator (110) configured for obtaining in electronic form a private random value (112, s), and generating the private key (114), the private key comprising the private random value (112), and a public key generator (120) configured for obtaining in electronic form a public set of bivariate polynomials (122, fi(,)), computing a public univariate polynomial (124) by summing over univariate polynomials obtained by substituting the private random value (112, s) into the polynomials of the public set (122, fi(s,)), and generating the public key (126), the public key comprising the public univariate polynomial (124) and the public set (122).

Abstract: The invention relates to a disaggregation apparatus (4) for being used in a multi-group electrical network (5), which comprises multiple electrical groups (1, 2, 3), each comprising one or more appliances (11, 12, 13, 21, 22, 23, 31, 32, 33). A determination unit (7) determines an electrical group (1, 2, 3) comprising an appliance, of which an operational state has been changed, based on first changes in mains voltages (V1, V2, V3) measured while the operational state change occurs, second and third changes in the mains voltages (V1, V2, V3) measured while switchable loads (1n, 2n, 3n) are switched, and the resistances (R1n, R2n, R3n) of the switchable loads (1n, 2n, 3n). Thus, a misdetection due to an operational state change of an appliance in another electrical group may be avoided and the accuracy of disaggregation may be improved in a multi-group electrical network (5).

Abstract: A first device (300) configured to determine a shared key with a second device (350). In cryptography, a key-agreement protocol is a protocol whereby two or more parties that may not yet share a common key can agree on such a key. The first device comprising a private correction function (?A( ), and a private univariate key polynomial (372, GA( ). From the private univariate key polynomial a correction function is derived from the correction function a correction factor derived. The intermediate key is modified to reduce the number of possible shared keys.

Abstract: The invention relates to a method for automatic grouping of light sources within an illumination system. The method is performed starting from a first light source of the illumination system emitting a first light signal and a first sound signal. The method includes steps of using an intensity of the first light signal as received by a second light source and an intensity of the first sound signal as received by the second light source to determine a value of a grouping function (410, 420), and assigning the first light source and the second light source to the same group of light sources when the determined value of the grouping function satisfies one or more pre-determined conditions (430, 440, 450). In this manner, a determination could be made whether or not the first and second light sources should be assigned to the same group in a manner that yields improved results over the prior art solutions.

Abstract: An apparatus and method (4,5,6,7,2) for capacitive measurement of electrophysiological signals (1) suppresses or reduces motion artifacts by providing a feedback mechanism. An average voltage between a capacitive sensor electrode (1) and the body (3) is controlled so as to reduce or minimize motion-induced signals.