1. A computer system configured to validate visual CAPTCHAs, the computer system comprising:
one or more hardware processors programmed, via executable code instructions, to implement:
a CAPTCHA generator module configured to generate a visual CAPTCHA comprising a moire pattern including a plurality of visual patterns in a first overlapping configuration, wherein at least one of the visual patterns is configured to be manipulated by a human user to update the moire pattern by combining the plurality of visual patterns in a second overlapping configuration that is different from the first overlapping configuration, and wherein at least one of the first overlapping configuration or the second overlapping configuration produce a secondary image including a first object that is not visible in separate visual patterns of the plurality of visual patterns, and wherein the moire pattern is configured to be perceived as including the first object by the human user viewing the moire pattern; and
a human validator module configured to:
receive user input data associated with the visual CAPTCHA,
compare the user input data to a description of the first object; and
determine whether the user input data was provided by a human based on said comparison.
2. The computer system of claim 1, wherein the plurality of visual patterns is automatically generated.
3. The computer system of claim 1, wherein the plurality of visual patterns is configured to be manipulated by the human user to a non-overlapping configuration.
4. The computer system of claim 1, wherein the plurality of visual patterns comprises a first set of concentric circle patterns and a second set of concentric circle patterns.
5. The computer system of claim 1, wherein the visual CAPTCHA is configured for display as part of a website.
6. The computer system of claim 1, wherein the visual CAPTCHA is configured to persistently display throughout a session.
7. The computer system of claim 6, wherein the persistent display of the visual CAPTCHA comprises visual alerts when user interaction is required.
8. The computer system of claim 1, wherein the visual CAPTCHA further comprises a first set of visual patterns and a second set of visual patterns, wherein a first answer to the first set of visual patterns is known and a second answer to the second set of visual patterns is unknown; and
wherein the user input data comprises a first input data corresponding to the first set of visual patterns and a second input data corresponding to the second set of visual patterns, and the human validator module is further configured to store the second input data based at least in part on the first input data.
9. A computer system configured to validate visual CAPTCHAs, the computer system comprising:
one or more hardware processors programmed, via executable code instructions, to:
generate a visual CAPTCHA including a plurality of visual patterns in a first configuration, wherein at least one of the visual patterns is configured to be manipulated by a human user to cause various amounts of overlapping of the visual patterns in order to produce different secondary images that are not visible in separate visual patterns of the plurality of visual patterns;
provide to the human user an indication of a target visual pattern to be created in a produced secondary image of the visual CAPTCHA;
receive input from the human user indicating a second overlapping configuration of the visual patterns that produces a moire pattern, wherein the moire pattern is configured to be perceived as including a first object by the human user viewing the moire pattern, and wherein an automated computer system analyzing the moire pattern cannot identify the first object;
compare the second overlapping configuration to a predetermined target overlapping configuration associated with the target visual pattern;
generate an indication of whether the second configuration was provided by a human based on said comparison; and
transmit the generated indication.
10. The computer system of claim 9, wherein the input from the human user is received based at least in part on interaction with a user interface.
11. The computer system of claim 10, wherein the user interface comprises an adjuster, and wherein the adjuster is movable to move one of the visual patterns in order to indicate the second overlapping configuration.
12. The computer system of claim 9, wherein the visual CAPTCHA comprises at least one of a vector image, scalable vector graphic, XML, graphics file, or an image file.
13. The computer system of claim 9, wherein the plurality of visual patterns comprises a first visual pattern, a second visual pattern, and a third visual pattern, wherein the first configuration corresponds to a non-overlapping configuration of the first visual pattern, the second visual pattern, and the third visual pattern, and wherein the second configuration corresponds to an overlapping configuration of the first visual pattern, the second visual pattern, and the third visual pattern.
14. The computer system of claim 9, wherein the visual CAPTCHA is configured for display as part of a website.
15. The computer system of claim 14, wherein the visual CAPTCHA is further configured to be fixed size, wherein rescaling a display including the visual CAPTCHA does not change a relative size of the visual CAPTCHA in the display.
16. The computer system of claim 9, wherein the visual CAPTCHA is configured to update after an elapsed time, and wherein a prompt is provided to the human user to manipulate the at least one of the visual patterns after the elapsed time.
17. Non-transitory computer storage comprising instructions for causing one or more computing devices to validate visual CAPTCHAs by:
generating a visual CAPTCHA including a plurality of visual patterns in a first configuration, wherein at least one of the visual patterns is configured to be manipulated by a human user to cause various amounts of overlapping of the visual patterns in order to produce different secondary images that are not visible in separate visual patterns of the plurality of visual patterns;
providing to the human user an indication of a target visual pattern to be created in a produced secondary image of the visual CAPTCHA;
receiving input from the human user indicating a second overlapping configuration of the visual patterns that produces a moire pattern, wherein the moire pattern is configured to be perceived as including a first object by the human user viewing the moire pattern, and wherein an automated computer system analyzing the moire pattern cannot identify the first object;
comparing the second overlapping configuration to a predetermined target overlapping configuration associated with the target visual pattern;
generating an indication of whether the second configuration was provided by a human based on said comparison; and
transmitting the generated indication.
18. The non-transitory computer storage of claim 17, wherein the input from the human user is received based at least in part on interaction with a user interface.
19. The non-transitory computer storage of claim 17, wherein the visual CAPTCHA is configured to update after an elapsed time, and wherein a prompt is provided to the human user to manipulate the at least one of the visual patterns after the elapsed time.
20. The non-transitory computer storage of claim 17, wherein the visual CAPTCHA is configured for display as part of a website.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An electromagnetic radiation receiving method, comprising:
modeling at least one signal within an electromagnetic radiation band;
generating at least one digital reference signal corresponding to the modeled at least one signal;
converting the at least one digital reference signal to at least one corresponding analog reference signal, wherein at least a delay and a magnitude of the at least one corresponding analog reference signal are controllable;
combining a received waveform within the electromagnetic radiation band containing the at least one signal and an information carrier with the at least one corresponding analog reference signal in a first analog combiner to generate a first residue signal, at least the delay and magnitude of the at least one corresponding analog reference signal being controlled such that a magnitude of the at least one signal within the first residue signal is reduced with respect to the received waveform and the information carrier is substantially undistorted;
generating at least one cancellation signal, corresponding to a residue of the at least one signal in the residue signal, controllable with respect to at least waveform, magnitude and delay based on a feedback input;
combining the first residue signal with the at least one cancellation signal in a second combiner to generate a second residue signal; and
generating the feedback input based on at least the second residue signal to control said generating the at least one cancellation signal with respect to at least waveform, magnitude, and delay and, such that a magnitude of the at least one signal within the second residue signal is reduced with respect to the first residue signal and the information carrier is substantially undistorted.
2. The method according to claim 1, wherein the at least one cancellation signal is an analog signal generated based on a second digital reference signal.
3. The method of claim 2, further comprising:
(a) digitally correlating the second residue signal with the second digital reference signal; and
(b) using the time-averaged digital correlation output to provide the feedback input as an adaptive feedback control of at least one of the magnitude and delay of the at least one cancellation signal.
4. The method of claim 3, further comprising applying an iterative algorithm to adjust at least one of the magnitude and delay of the at least one cancellation signal, in order to reduce the time-averaged digital correlation output toward zero.
5. The method of claim 1, wherein the digital reference signal is provided by the source signal of an interference signal transmitter.
6. The method of claim 5, wherein the at least one corresponding analog reference signal comprises a linear combination of plurality of representations of a signal having respectively different magnitudes and delays.
7. The method according to claim 1, wherein the at least one signal comprises a multipath interference signal, and wherein the at least one corresponding analog reference signal comprises a plurality of representations of the digital reference signal differing in respective magnitude and delay.
8. The method of claim 1, further comprising digitizing the second residue signal using a superconducting analog to digital converter.
9. The method of claim 1, wherein the at least one cancellation signal is generated based on a digital lookup table which is adaptively updated.
10. The method of claim 1, further comprising a limiter which limits a power of the first residue signal before it reaches the second combiner.
11. The method of claim 1, wherein a dynamic range of the second residue signal with respect to a lowest information carrying amplitude of the information carrier is reduced with respect to the received waveform.
12. The method of claim 1, wherein the second combiner comprises a superconducting transformer having at least three coils.
13. The method according to claim 1, wherein second residue signal is reduced by at least 60 dB with respect to the at least one signal.
14. An electromagnetic radiation receiver, comprising:
at least one digital processor configured to model at least one signal within an electromagnetic radiation band and generating at least one digital reference signal corresponding to the modeled at least one signal, wherein at least a delay and a magnitude of the at least one corresponding analog reference signal are controllable;
an analog component configured to convert an output of the digital processor of the generated at least one digital reference signal to at least one corresponding analog reference signal;
a first analog combiner configured to combine a received waveform within the electromagnetic radiation band containing the at least one signal and an information carrier, with the at least one corresponding analog reference signal, to generate a first residue signal, at least the delay and magnitude of the at least one corresponding analog reference signal being controllable such that a magnitude of the at least one signal within the first residue signal is reduced with respect to the received waveform and the information carrier is substantially undistorted;
a second combiner configured to combine the first residue signal with at least one cancellation signal to generate a second residue signal; and
the at least one digital processor being further configured to generate the at least one cancellation signal, corresponding to a residue of the at least one signal in the residue signal, controlled with respect to at least waveform, magnitude and delay based on a feedback input from the second residue signal, such that a magnitude of the at least one signal within the second residue signal is reduced with respect to the first residue signal and the information carrier is substantially undistorted.
15. The system of claim 14, further comprising:
(a) a digital correlator configured to correlate the digitized second residue signal with the second digital reference signal; and
(b) the at least one digital processor further comprising an adaptive feedback control, configured to receive an output of the digital correlator, and to adjust at least one of the magnitude and delay of the at least one cancellation signal in dependence thereon.
16. The receiver of claim 15, wherein the at least one digital processor is further configured to perform an iterative algorithm to adjust at least one of the magnitude and delay of the at least one cancellation signal, in order to reduce toward zero a time-averaged digital output of the digital correlator.
17. The receiver according to claim 14, wherein the at least one signal comprises a multipath interference signal, and wherein the at least one digital processor generates at least one digital reference signal as a plurality of representations of a common digital reference signal differing in respective magnitude and delay.
18. The receiver of claim 14, further comprising a limiter configured to restrict at least a portion of a power of the coarse residue signal from the fine combiner when the power of the coarse residue signal exceeds a threshold, wherein the fine combiner comprises a superconducting transformer with at least three coils, and wherein the at least one digital processor comprises an adaptively updated a digital lookup table for generation of the at least one cancellation signal, wherein the digitizer comprises a superconducting analog to digital converter having a dynamic range, the dynamic range being insufficient to extract information from the information carrier, wherein the magnitude and delay of the digital reference signal and the at least one cancellation signal are adjusted such that the dynamic range of the digitizer is sufficient to detect the information from the information carrier in the second residue signal.
19. A receiver, comprising:
(a) an input configured to receive an analog signal comprising an information carrier and at least one signal within an electromagnetic radiation band;
(b) a first combiner configured to combine the analog signal with a first signal to produce a first combined signal with a reduced power of the at least one signal with respect to the input, substantially without distortion of the information carrier;
(c) a second combiner configured to combine the first combined signal, received by the second combiner substantially without introduction of intermodulation product of the analog signal and the first signal, with a second signal to produce a second combined signal with a reduced power of the at least one signal with respect to the first combined signal, substantially without distortion of the information carrier;
(d) a digitizer, configured to digitize the second combined signal while substantially retaining information corresponding to the information carrier; and
(e) a feedback controlled signal generator, configured to receive a representation of the digitized second combined signal, and control a generation of at least one of the first signal and the second signal.
20. The receiver of claim 19, further comprising at least one superconducting device selected from the group consisting of a digital processor, a digital correlator, an analog to digital converter, and a transformer.
21. The receiver of claim 19, wherein the feedback controlled signal generator comprises a digital correlator which is configured to determine a characteristic delay of the at least one signal, and to control a delay of a component of the second signal with respect to the characteristic delay to the at least one signal.