1706results about "Digital function generators" patented technology

A system and method of determining locations of one or more RFID tags within an RFID environment. The system includes a plurality of RFID readers, each operative to transmit and receive RF signals for scanning a tag disposed within an RF coverage region associated with the reader, and for receiving tag data in response to the scanning of the tag. A plurality of sub-locations is determined within the environment, each corresponding to at least a portion of at least one of a plurality of RF coverage regions associated with the readers. The sub-locations are mapped to a plurality of predefined locations within the environment. A reader scans a tag, and receives tag scan data from the tag in response to the scanning of the tag. The tag scan data includes a tag identifier associated with the scanned tag. The tag scan data is mapped to the sub-locations based on the RF coverage region associated with the reader. The location of the scanned tag is then determined with reference to the predefined locations within the environment, based on the tag identifier included in the tag scan data, the mapping of the tag scan data to the sub-locations, and the mapping of the sub-locations to the predefined locations.

A computationally generated playing card sequence (e.g., pseudo-random, non pseudo-random, or partially pseudo-random) allows shuffled distribution of playing cards. Playing cards may be organized into card holders by at least one or a rank and a suit, and retrieved in the computationally generated order. Alternatively, playing cards may be organized into card holders in order of a computationally generated sequence, and retrieve as necessary. Unreadable playing cards may be automatically removed from play.

A robust computational secret sharing scheme that provides for the efficient distribution and subsequent recovery of a private data is disclosed. A cryptographic key may be randomly generated and then shared using a secret sharing algorithm to generate a collection of key shares. The private data may be encrypted using the key, resulting in a ciphertext. The ciphertext may then be broken into ciphertext fragments using an Information Dispersal Algorithm. Each key share and a corresponding ciphertext fragment are provided as input to a committal method of a probabilistic commitment scheme, resulting in a committal value and a decommittal value. The share for the robust computational secret sharing scheme may be obtained by combining the key share, the ciphertext fragment, the decommittal value, and the vector of committal values.

A DTMF signal generating circuit is provided with a frequency designating unit which designates frequencies to form a DTMF signal, a sinusoidal wave computing unit which computes sinusoidal waves by referring to frequencies designated by the frequency designating unit, and a sinusoidal wave synthesizing unit which synthesizes two sinusoidal waves computed by the sinusoidal wave computing unit. The sinusoidal wave computing unit is provided with operators such as an adder-subtracter and a multiplier and generates a sinusoidal wave by determining terms of a Taylor expansion of a sinusoidal function by arithmetic operation.

A random number generator having a simple construction which generates physical random numbers necessary for encryption. The random number generator has an amplifier to amplify noise signals generated from a noise source and digitizer to digitize the amplified noise signals. The digitizer includes a serial register.

A method and apparatus for generating random numbers for use in electronic applications is disclosed. A given sequence of random binary numbers of a certain length can be decoded into several random numbers for a specific application. The upper range values of the random numbers to be decoded determine the number of bits required for the generation of the these random numbers. In the decoding process, the given random binary number divides a range value to generate a remainder and a quotient. The quotient becomes the new random binary number for the generation of other random numbers while the remainder is the generated random number. The process then repeats to generate other random numbers. At the end of the generation process, the last quotient determines the validity of the generated random numbers.

A computationally generated playing card sequence (e.g., pseudo-random, non pseudo-random, or partially pseudo-random) allows shuffled distribution of playing cards. Playing cards may be organized into card holders by at least one or a rank and a suit, and retrieved in the computationally generated order. Alternatively, playing cards may be organized into card holders in order of a computationally generated sequence, and retrieve as necessary. Unreadable playing cards may be automatically removed from play.

An apparatus and method for generating pseudo-random cryptographic keys in a cryptographic communications system, whereby, given a common set of initializing configuration data, the pseudo-random cryptographic keys can be duplicatively generated by various independent pseudo-random key generators of the cryptographic communications system. In accordance with the preferred embodiment of the present invention, users of the communications system can each possess an independent pseudo-random key generator to securely communicate with other users also holding independent pseudo-random key generator that share the same initialization configuration data, no matter where the other users are located or whether the users are connected via wire or wireless communication network. The present invention facilitates secure communication without the need to transport decryption keys in advanced, thereby reducing the risk of the secure communication becoming compromised via interception of decryption keys.

A wideband signal generator according to one embodiment of the invention includes a variable frequency source and a direct digital synthesizer. Local oscillators, signal analyzers, modulators, demodulators, and other equipment including one or more such generators are also disclosed.

Embodiments of the present invention provide an apparatus and method of generating electrical stimulation waveforms using Direct Digital Synthesis (DDS). The waveform generation substantially reduces intensive processor calculations and commands required for the generation of waveforms via Pulse Width Modulation (PWM). DDS technology is integrated into single-integrated circuit components, capable of generating waveforms based on singular digital word commands. The use of DDS integrated circuits allows for rapid changes in frequencies, automatically sweeps frequencies between user defined limits, and are capable of a wide range of frequencies. Further, utilization of DDS in waveform generation allows for software updatable functionality. Additionally, because DDS technology outputs a smooth sine wave, the need for extensive filtering is drastically reduced. Further, DDS technology can be utilized in an amplitude modulation stage beyond the DDS waveform generator, further reducing the burden on processor systems.

Circuitry which performs modular mathematics to solve the equation C=Mk mod n and n is performed in a manner to mask the exponent k's signature from timing or power monitoring attacks. The modular exponentation function is performed in a normalized manner such that binary ones and zeros in the exponent are calculated by being modulo-squared and modulo-multiplied.

Provided is an information security apparatus (1100) that has enhanced stability and confidentiality of a hash key. The information security apparatus (1100) includes an information generating PUF unit (1104) that has tamper resistance set, using physical characteristics, so as to output a preset hash key, a partial error-correction information storage unit (1107) that stores partial error-correction information, an error correcting PUF unit (1106) that has tamper-resistance set, using physical characteristics, so as to output error-correcting PUF information, an error-correction information generating unit (1108) that generates error-correction information using partial correction information and the error-correcting PUF information, and an error correcting unit (1105) that corrects an error for the hash key outputted from the information generating PUF unit (1104) and outputs an error-corrected hash key.

A random number generator comprising an oscillator with an output signal dependant upon a random source, a sampling device to sample the output signal from the oscillator to obtain a sampled oscillator output, and a fixed frequency clock driven linear feedback shift register (LFSR) communicatively coupled to the sampling device via a digital gate to receive the sampled oscillator output, and to provide a random number at an output of the LFSR. Additionally, the random number generator may comprise an optional mixing function communicatively coupled to the LFSR to read the random number, and to insert the random number into an algorithm to obtain a robust random number.

Signal processing devices and methods estimate transforms between signals using a least squares technique. From a seed set of transform candidates, a direct least squares method applies a seed transform candidate to a reference signal and then measures correlation between the transformed reference signal and a suspect signal. For each candidate, update coordinates of reference signal features are identified in the suspect signal and provided as input to a least squares method to compute an update to the transform candidate. The method iterates so long as the update of the transform provides a better correlation. At the end of the process, the method identifies a transform or set of top transforms based on a further analysis of correlation, as well as other results.

A microelectronic apparatus and method for generating random binary words including at least one clocked pseudorandom binary number sequence generator normally operative to generate a cyclic output sequence of binary numbers, each number including a string of binary symbols, the cyclic output sequence including a basic sequence which is generated repeatedly, at least one bit stream generator generating a clocked bit stream including a stream of binary symbols of a first type occasionally interrupted by a binary symbol of a second type, wherein a first varying time interval between the occasional interruptions is intractably correlated to the output sequence of the number sequence generator, wherein each occurrence of an interruption of the stream of binary symbols of the first type by a binary symbol of the second type causes a pseudorandom modification of the cyclic output sequence of the number sequence generator and a sampling device operative to sample the cyclic output sequence of binary numbers thereby to generate a sampled output sequence including at least one sampled binary word.

Systems and methods are disclosed, especially designed for very compact hardware implementations, to generate random number strings with a high level of entropy at maximum speed. For immediate deployment of software implementations, certain permutations have been introduced to maintain the same level of unpredictability which is more amenable to hi-level software programming, with a small time loss on hardware execution; typically when hardware devices communicate with software implementations. Particular attention has been paid to maintain maximum correlation immunity, and to maximize non-linearity of the output sequence. Good stream ciphers are based on random generators which have a large number of secured internal binary variables, which lead to the page synchronized stream ciphering. The method for parsed page synchronization which is presented is especially valuable for Internet applications, where occasionally frame sequences are often mixed. The large number of internal variables with fast diffusion of individual bits wherein the masked message is fed back into the machine variables is potentially ideal for message authentication procedures.

An optical medium, such as fiber, is tapped to provide an antenna port wherever radio service coverage is desired. Each antenna port is a bi-directional remote unit that receives a digital optical signal from a host unit and transforms the signal to a radio frequency signal for transmission by the remote unit. The remote unit receives radio frequency signals that are converted to digital signals and summed with signals from other remote units and converted to an optical signal for transmission to the host unit.

Systems and methods for generating and displaying a keyboard comprising a random layout of keys are described here. One embodiment includes displaying a keyboard comprising a random layout of keys, to receive a user entered key phrase to be entered to gain access to secure data, and receiving the user entered key phrase by the user selecting keys of the keyboard via a pointing input device. The displaying includes, individually mapping keys of the keyboard to a separate value within a first value range, selecting a key for the keyboard based on the random value generated, and repeating the generating the random value and selecting a key for the keyboard based on the random value to select a remainder of keys for generating the random layout of keys for the keyboard.

A quantum noise random number generator system that employs quantum noise from an optical homodyne detection apparatus is disclosed. The system utilizes the quantum noise generated by splitting a laser light signal using a beamsplitter having four ports, one of which receives one of which is receives the laser light signal, one of which is connected to vacuum, and two of which are optically coupled to photodetectors. Processing electronics process the difference signal derived from subtracting the two photodetector signals to create a random number sequence. Because the difference signal associated with the two photodetectors is truly random, the system is a true random number generator.

Pseudo-random numbers (PRNs) generated by a PRN generator are mapped to predefined number ranges or target ranges. The target range may be smaller or larger than the range of the PRN generator. Mapping to a smaller target range may include generating PRNs (e.g., integers) from a particular bit-input stream (e.g., 32-bit) having a uniform distribution across the range of numbers; selecting an optimal subset of the generated PRNs to map; and mapping the selected PRNs to a corresponding number in a target range such that the mapped numbers are uniformly distributed across the target range. Mapping to a larger target range may include generating uniformly distributed PRNs; applying a generation function to the PRNs to generate uniformly distributed packed numbers; and applying a mapping function to map selected packed numbers to the target range such that the mapped numbers are uniformly distributed.

Techniques to improve the acquisition process in a spread spectrum environment. The signals from different CDMA systems are spread with different sets of PN sequences, with the PN sequences in each set being uncorrelated to the PN sequences in the other sets. By using uncorrelated PN sequences, the likelihood of detecting a pilot signal from an undesired system is reduced or minimized, and the mean time to acquisition of the pilot signal from the desired system is improved. The mobile station can attempt to acquire the pilot signal by processing the received signal with a first set of PN sequences corresponding to a first hypothesis of the particular signal being acquired. If acquisition of the pilot signal fails, a second set of PN sequences corresponding to a second hypothesis is selected and used to process the received signal. The PN sequences in the second set are uncorrelated to the PN sequences in the first set. The PN sequences for the first set can be generated based on the characteristic polynomials defined by IS-95-A, and the PN sequences for the second set can be the reverse of the PN sequences for the first set.

A method and an apparatus capable of realizing at a high speed an elliptic curve cryptography in a finite field of characteristic 2, in which the elliptic curve is given by y2+xy=x3+ax2+b (b≠0) and an elliptic curve cryptography method which can protect private key information against leaking from deviation information of processing time to thereby defend a cipher text against a timing attack and a differential power analysis attack are provided. To this end, an arithmetic process for executing scalar multiplication arithmetic d(x, y) a constant number of times per bit of the private key d is adopted. Further, for the scalar multiplication d(x, y), a random number k is generated upon transformation of the affine coordinates (x, y) to the projective coordinates for thereby effectuating the transformation (x, y)→[kx, ky, k] or alternatively (x, y)→[k2x, k3y, k]. Thus, object for the arithmetic is varied by the random number (k).

A system that has a pseudorandom number generator and a mapping system. The pseudorandom number generator generates a random number that is mapped by the mapping system to an output value that is selected from a set of predetermined output values. To increase the randomness of the sequence of numbers generated by the pseudorandom number generator, a tap and / or seed value of the pseudorandom number generator can be varied.

A server is configured for preventing flood attacks by a client having sent a request, by dynamically generating a challenge to be performed by the client before the server will perform any work for the client. The challenge includes a dynamically generated computational request and a dynamically generated secure cookie. The server generates a first hash result based on hashing a first random number, having a prescribed length, with a second random number having a dynamically selected length. A secure cookie is generated based on hashing the first hash result with a prescribed secure key known only by the server, and a unique identifier for the request such as the client network address with a time stamp. The challenge requires the client to determine the second random number based on the first random number and the hash result. The server validates the challenge results using the secure cookie.

A method is provided for generating a chaotic sequence. The method includes selecting a plurality of polynomial equations. The method also includes using residue number system (RNS) arithmetic operations to respectively determine solutions for the polynomial equations. The solutions are iteratively computed and expressed as RNS residue values. The method further includes determining a series of digits in a weighted number system (e.g., a binary number system) based on the RNS residue values. According to an aspect of the invention, the method includes using a Chinese Remainder Theorem process to determine a series of digits in the weighted number system based on the RNS residue values. According to another aspect of the invention, the determining step comprises identifying a number in the weighted number system that is defined by the RNS residue values.

A method for generating a local interface key includes: generating a variable parameter; and deriving the local interface key, according to the variable parameter generated and related parameters for calculating the local interface key. The method simplifies the process in which the terminal obtains the local interface key and the system resources are saved. Moreover, the local interface key is derived through the variable parameter and the valid key information. Thus, the security level between the UICC and the terminal is ensured.