Koninklijke Philips Corporation N.V.

Nxp B.v.

Frank Boeh

Juergen Nowottnick

Martin S Wilcox

The invention relates to a method for cryptographic authentication in access security systems. The aim of the invention is to provide a software solution. To this end, the method for secured storage of counter states in a non-volatile memory (EEPROM) () involves an incrementing () process, and the current counter state is updated in only one EEPROM segment following each incrementing process (), a subsequent access to the EEPROM () only being enabled in the event of a successful incrementing () of an EEPROM-based counter.

Method for cryptographic authentication

First and second devices () are configured to transmit and receive signals wirelessly and have first and second clocks respectively for determining signal transmission and arrival times. The first device transmits first and second signals () and the second device transmits a third signal (). By introducing a delay into the first signal, a thief may be able to fool the devices into thinking that they are closer than they really are. To help identify if a delay has been introduced into the first signal, the first device calculates a ratio of clock rates for the first and second clocks and determines whether the calculated ratio falls within a predefined range.

Arrangement and method for ascertaining whether a set of measurements is acceptable for use in determining a time of flight of signals

In order to further develop a system () and a method for calibrating the clock frequency of at least one clock generator unit (), in particular oscillator unit, that is assigned to at least one transmitting/receiving module (), wherein&#x2014;the transmitting/receiving module () communicates with at least one microcontroller unit () over at least one data line () and&#x2014;the clock generator unit () is assigned at least one calibration unit (), in such a manner that with significantly reduced system costs the clock frequency of the clock generator unit () can be calibrated with very high accuracy, it is proposed that&#x2014;in order to calibrate the clock frequency of the clock generator unit () at least one calibration unit () is assigned to the clock generator unit), &#x2014;the calibration unit () can be set in binary terms by means of at least one command signal (COM) via the data line (), &#x2014;the clock generator unit () is assigned at least one binary counter () that is clocked by the clock generator unit (), in particular by the output frequency (fout) of the clock generator unit () and&#x2014;within the transmitting/receiving module () there is at least one control logic mechanism () which is connected (STA, OFL or SET) to the calibration unit () or to the binary counter (), which control logic mechanism, following reception of the command signal (COM), resets the binary counter (), starts it (STA) and awaits the expiry or overflow (OFL) of the binary counter ().

System and method for calibrating the clock frequency of a clock generator unit over a data line

Method for realizing a binary counter that changes a partly permuted data word stored in a non-volatile memory and including a counter and a working memory and storing a data word in the form of memory words in the non-volatile memory. The method further comprises reading the memory words of the data word and storing the memory words in the working memory while performing an inverse reordering of k permutation bits of the data word, applying an inverse bijective mapping function to the k permutation bits of the data word, altering the data word, applying a bijective mapping function to the k permutation bits of the data word, performing a reordering of the k permutation bits, and checking each memory word for deviations from the memory word stored in the non-volatile memory and storing only those memory words in the non-volatile memory again for which this is the case.

Binary counter

In an arrangement for storing a count, which comprises a non-volatile memory ( ) which has at least 3 memory segments ( ), a controller ( ) is provided which stores a new count in one of the memory segments ( ), the controller ( ) for selecting this memory segment ( or) searching for the memory segment whose stored value has a larger difference from the stored values of the other memory segments than the stored values of the other memory segments and which controller, should such a segment exist, selects this segment for storing the new count. If, conversely, no such segment exists, the controller selects a memory segment ( ) in accordance with a selection instruction oriented to the memory contents.

Arrangement for storing a count

An arrangement for a passive keyless entry system is disclosed, comprising a base station and a portable data carrier, wherein the data carrier and the base station are configured to determine authorized access of the base station, wherein first and second position information of the relative position of the data carrier with respect to the antenna coils and UHF receiver stages of the base station is gained from measurements of the low-frequency, magnetic alternating fields transmitted by LF transmitter stages of the base station to the data carrier, and the UHF signal transmitted by a UHF transmitter stage of the data carrier to the base station, wherein a signal representing authorized access is generated by the base station when both position information components differ by less than a predetermined extent.

Passive keyless entry system

The invention relates to an arrangement for position assignment of vehicle wheels ( ), in which means ( ) for detecting the number of rotations and turning direction of the wheel ( ) are assigned to each wheel ( ). In accordance with two further embodiments, a steering sensor ( ) is provided instead of the means for detecting the turning direction of the wheel. In all embodiments, the vehicle is provided with an evaluation unit ( ) which, in the case of a curved trajectory of the vehicle ( ), performs a vehicle position assignment of the individual wheels ( ) with reference to the number of rotations and turning directions detected for each wheel ( ) and possibly with reference to the steering direction.

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Buchholz, Germany

Frank Boeh