Deutschetelekom Ag

Klaus Huber

Matthias Baumgart

Tim Schneider

Matthias Gunkel

Friedrich Toensing

Ralf Schaffelhofer

Eva Saar

Alfred Scheerhorn

Peter Windirsch

Bernhard Loehlein

Heiko Knospe

Karl-Heinrich Hofmann

Jörg Schwenk

J&ouml;rg Schwenk

Bernhard LÖHLEIN

The invention relates to a method and a communication system for releasing a data processing unit used for processing project data of a selected project. In order to obtain project-related release of a data processing unit (), a client requests a user right for the data processing unit () used for processing the project data that is part of a predetermined project. A first signature (I) is verified as to the correctness thereof. The data processing unit () is released to process the project data that is part of the selected project only if the verification process has established that the first signature (I) is correct.

Method and communication system for releasing a data processing unit

The present invention relates to an asymmetrical encryption method. The public key is made up of a large composite number n; the private key is made up of the factors of the composite number. The encryption is made up of a number of iterations of individual encryption steps that are successively reversed during the decryption. In this context, the reversal of an individual encryption step requires the solving of a quadratic equation modulo m [sic]. The private key is preferably made up of the large prime numbers p and q. The public key is the product n of these two prime numbers, as well as a comparatively small integer L which is greater than one. The message m is made up of two integral values mand m, thus=(, m),both values being in the set Z={0, 1, 2, . . . , n&#x2212;1}. The encryption is accomplished via the equation().

Encryption method based on factorization

An analog circuit system for generating output signals whose curve shape, at least sectionally, corresponds or is approximate to an elliptic function. Standard analog components such as adders, integrators, multipliers and differential amplifiers can be interconnected in order to simulate elliptic time functions from the standpoint of circuit engineering.

Analog circuit system for generating elliptic functions

A method for modulating a carrier signal used for transmitting analog or digital message signals is provided. The module k of elliptic functions is used as a modulation parameter instead of the amplitude or the frequency. The carrier signal modulated according to this modulation method is provided with a constant amplitude and a fixed frequency while the signal form is chronologically modified at the rhythm of the message that is to be transmitted.

Method for modulating a carrier signal and method for demodulating a modulated carrier signal

A method for representation, interpolation and/or compression of data includes identifying a two-dimensional interpolation function s(z) based on a sampling function a(z). A Cauchy integral theorem is applicable for the interpolation function s(z). The interpolation function s(z) is used for the representation, interpolation and/or compression of the data.

Method for two-dimensional representation, interpolation and compression of data

A method and/or system for transmitting sequences of signals/data from a transmitter to a receiver and for authenticating the sequences of signals/data may consist of a precalculation phase and of a communication phase in which the signals are transmitted together with the checking sums. In the precalculation phase, a pseudo-random sequence may be first generated by means of a cryptographic algorithm from a time-variable parameter and other initialization data. Non-overlapping sections (z() of a sequence (z) having each m bits may be associated to signals (s(i)), wherein i=1, 2, . . . n, of a signal storage. Further non-overlapping m bit sections (t(i)) of the remaining sequence may be selected for coding numbers (1, 2, . . . MAX). The transmitter may transmit the initialization information and the time-variable parameters to the receiver and the receiver may calculate the pseudo-random sequence (z) and checks the receiver authentication token (T). The transmitter may accept the received signals as being authentic when the received authentication tokens match the calculated ones.

Method of transmitting signals

A method and circuit arrangement for transmission of messages in which a number of L components (m, . . . , m) are coded by means of orthogonal functions to a signal (s(t)), and in which approximations of hermitic functions are used as orthogonal functions. A Fourier transform is performed on the received signal and subsequently decoded with the aid of the orthogonal functions.

Method and circuit layout for the transmission of messages by means of approximating hermitian functions

A method and a circuit arrangement for efficient use of multistage modulation methods using orthogonal base functions for the representation of a signal to be transmitted. Signal points of a signal constellation are selected according to a respective predetermined and/or selected probabilities so as to optimize a respective signal energy and/or a respective signal data rate, the selected signal points each having a defined respective energy. A 16-QAM signal constellation can be used, for example, for transmitting at low data rates. In the circuit arrangement, a source () which supplies a data stream () and is connected to a code converter () for converting the data stream. The output of the code converter () is connected to a modulator () in which the corresponding signal points are selected according to the respective probabilities. The data stream () is then transmitted over a channel (), and a demodulator () situated downstream from a code converter () carries out the inverse operation.

Method and circuit arrangement for improved data transmission

A method for generating a digital signature s of a message m using a secret key including at least two large prime numbers p, q is provided. It is provided that s is the zero of the polynomial P(x)&#x2212;m modulo n, P(x) being any permutation polynomial modulo n.

Process for generating a digital signature and process for checking the signature

The invention relates to a method of encrypting and decrypting information using a public key and a secret key. The invention is characterized in that the secret key consists of two very large primary numbers while the public key consists of the product of both primary numbers and a permutation polynomial.

Method for encrypting information represented as a numerical value

In a method for compressing data, in which, in a data stream composed of characters, character strings are checked for correlation with other character strings that are present at a given distance in the data stream, and in which, in each case, the number of correlating characters and the position of the correlating characters within the respective other character string constitute the compressed data, at least one character is allowed to differ in the correlation check and data for correcting the at least one differing character is inserted into the compressed data.

Method for compressing data

With reference to a method and circuit arrangements, it is described how, using the Chebyshev polynomials, frequency multipliers as well as sine/cosine generators can be constructed in a general-purpose manner, i.e., circuits that are frequently required in telecommunications engineering. A number of Chebyshev modules and various multipliers and adders are realized in an integrated circuit which then carries out a wide range of different functions depending on the external wiring. Disclosed as further functions which can easily be technically realized with such a chip are the synthesis of any desired functions by representing the function by means of a Chebyshev series and the use of T (x) as an amplifier with the amplification factor n for sin(nx)&ap;nx, and odd n.

Method and circuit configuration for producing sinusoidal/cosinusoidal oscillations

A method and circuit arrangement for frequency multiplication. A plurality of circuit modules for realizing Chebyshev polynomials of the nth order T,(x)) are provided. The Chebyshev polynomials have arithmetic properties and are defined by T,(cos(&ohgr;t))&equals;cos(n&ohgr;t). The circuit modules are interconnected to form a modular circuit array or a modular circuit structure using one or more of the relations T,(x)&equals;T,(T,(x)) and T,(x)&equals;T,(x)T,(x)&minus;T,(x). A cosinusoidal oscillation of a frequency is input into the Chebyshev circuit module (T,(x)) to generate a cosinusoidal oscillation having n-fold frequency. Frequency multiplier circuits may be produced very simply and in modular form, making applications in telecommunications, in particular, very cost-effective.

Method and circuit arrangement for multiplying frequency

In a method for verifying the instant that a transaction is implemented or that a document is created, signed, sent and/or received, it is provided for a time marker to be inserted into the document in a tamper-proof manner, and for the time marker to correspond to a time stamp taken from a non-adjustable clock. An arrangement for performing the method is also provided.

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Darmstadt, Germany

Klaus Huber