Abstract: A system may be configured to prepare and use prediction models for predicting existence of fingerprints among encrypted traffic. Some embodiments may: obtain a machine learner configured to identify statistical differences between pseudo-randomness associated with encrypted user data and higher-entropy randomness associated with a set of other data; determine at least a portion of a path traversed by the encrypted user data in the network based on the identification; and secure the network based on the determination.

Abstract: Described herein are systems for radio-frequency (RF) localization. The systems developed by the inventors are designed to improve the accuracy of RF localization to millimeter and sub-millimeter ranges, and additionally, are designed to do so while also limiting manufacturing costs. The RF localization systems developed by the inventors leverage the relatively low costs associated with the manufacturing of printed circuit board assemblies (PCBAs). Manufacturing RF localization devices using PCBAs poses a number of challenges, including large minimum feature size and the presence of surface waves. Described herein are techniques for addressing challenges arising in connection with RF localization devices fabricated using PCBAs. One technique involves the use of slot-fed antennas, which makes the device efficient notwithstanding the large minimum feature size. Another technique involves the use of frequency selective surfaces for suppressing surface waves.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: The present disclosure pertains to a system configured to prepare and use prediction models for predicting existence of fingerprints among encrypted traffic. Some embodiments may: obtain a machine learner configured to identify statistical differences between pseudo-randomness associated with encrypted user data and higher-entropy randomness associated with a set of other data; determine at least a portion of a path traversed by the encrypted user data in the network based on the identification; and secure the network based on the determination.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: Techniques for designing radio-frequency (RF) antennas for use in micro-localization systems are described. The techniques described herein allow RF designers to estimate how accurate a micro-localization system using the designed antenna will be once manufactured. As such, the techniques described herein enable RF designers to iterate the design of an RF antenna, for example by adjusting certain antenna design parameters in an iterative fashion, until a satisfactory degree of accuracy is achieved. In particular, described herein is angular impulse delay (AID), a metric that quantifies the time delay existing between the emission of an electromagnetic wave at a certain point in space and the reception of this electromagnetic wave at the assumed phase center of the antenna. The benefit of AID is that it allows RF designers to quantify the difference in the delays between different points in space and the phase center of an antenna.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first center frequency and transmitting RF signals having a second center frequency, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first center frequency received from the output port to second RF signals having the second center frequency and to provide them to the coupled port.

Abstract: A two-way feeder for use in an aquarium. The feeder has a base that can be buried in sand or crushed coral in an aquarium. One or more fittings on the underside of the base provides a user of the feeder with the option of applying one or more suction cups to the feeder. The suction cups are used to attach the feeder in different surfaces of the aquarium, including the bottom surface and the side walls. The feeder can be used as to attach food in at least two ways. First, buoyant foods such as cucumber can be secured to the top of the device by screwing the cucumber over the head of the threaded receiver. Second, leafy foods such as lettuce or seaweed can be secured by a spring clip associated with an adapter that is compatible with and screwed onto the threaded receiver.