Abstract: A method and a device are provided, in particular a transponder, for generating a random number by a linear feedback shift register, wherein a first seed is generated by means of a first automaton, a second seed is generated by means of a second automaton, the first and second automata operate using different functional principles, so that the first and second seeds have different properties, and the shift register is reloaded with the first and/or second seed.

Abstract: A transponder receives its operating energy from an external source such as a radio signal or a battery. Such transponders are used for example in a vehicle or in a remote sensor. The response range of the transponder is increased by converting the received energy into an operating voltage which in turn is used to generate a function voltage required for performing a current function sequence. The generated function voltage is checked to determine at least one characteristic of the generated function voltage. The determined function voltage characteristic, for example a voltage value directly representing the function voltage, is then used to acknowledge or reject a result of performing the function sequence. Thus, the time duration for performing any current function sequence is flexibly adapted to the current requirements of that function sequence, whereby the power consumption of the transponder is optimally reduced and the response range respectively increased.

Abstract: A method for protecting a product against counterfeiting is provided that has a transponder associated with the product, upon which at least one unique identifier is stored, wherein a flag in a set or cleared state is associated with the identifier, and when the flag is set, read access to the identifier by a reader is only permitted after authentication. The invention further relates to a transponder for protecting a product against counterfeiting.

Abstract: A method for the at least temporary activation of bidirectional communication between a transponder having a nonvolatile memory area and a base station, whereby the transponder in an at least partial mute state receives messages, but no information-related data from the nonvolatile memory area are transmitted and for activation a data stream is transmitted to the transponder by the base station, wherein the data stream for a transmission is linked with a symmetric password, the enable signal is extracted by the transponder with the symmetric password from the received data stream, and the transponder is activated at least temporarily after the enable signal has been verified as valid. The invention relates further to a transponder having means for carrying out this type of procedure.

Abstract: A storage circuit arrangement for a semi-passive or passive RFID transponder is provided. In prior-art circuit arrangements, storage capacitors are routinely discharged in an undefined fashion via leakage currents for a control mode of the transponder, so that the persistence times depend greatly on the ambient temperature and on existing manufacturing tolerances. It is proposed according to an embodiment to charge a first electrical storage device with a first reference voltage and then to discharge it again in a defined fashion during a time t via discharge device. Advantageously, in addition a storage mode of the first storage device to hold the control mode can be transmitted in a controlled fashion via a switching device to a second storage device with C2<<C1 to shorten a settle time and to accelerate the anticollision.

Abstract: A backscatter transponder for an HF communication system with modulated reradiation, is provided that includes an antenna for receiving high-frequency carrier signals, wherein the antenna has reflective characteristics, a control unit for providing transponder-specific parameters, and a modulator that can be driven by the control unit. The modulator altering the reflective characteristics of the antenna in accordance with at least one transponder-specific parameter.

Abstract: For transmitting data between a base station and a transponder, information packets modulated onto an electromagnetic carrier wave each include a header section, a middle section, and an end section. The data are encoded in the middle section using information symbols, e.g. representing digital “1s” and “0s”. The header section of at least the first packet defines the number and unique identifications of all of the symbols that will be used for encoding the data in the middle section of this and/or subsequent packets. This transmission protocol defined in the header section can be varied in subsequent packets to adaptively adjust the transmission rate depending on the existing communication conditions and requirements such as high frequency regulations prescribed by national law. The transmission rate can be considerably increased, in comparison to a transmission rate that would otherwise be necessary for achieving a reliable transmission even under unfavorable conditions.

Abstract: Data encoded in packets modulated onto a carrier wave is transmitted between a base station and a transponder. Each packet includes a header section containing at least a reference symbol, and a further section such as a data section. In the transponder, the time duration of the reference symbol is determined, and a parameter is adjusted dependent on the determined duration. The parameter determines at least a property, such as the time resolution, of the encoding and/or decoding operation, and may be the clock frequency of a counter circuit or the charging current of an RC-circuit used to determine the duration of the symbols. The parameter may initially be set to a minimum default value, which is increased if the determined duration is less than or equal to a specified threshold. Thereby, power consumption is minimized while ensuring reliable encoding and decoding over a large range of transmission distances.

Abstract: A method and apparatus for wireless data transmission between a base station and one or more, in particular, passive and/or backscatter-based transponders, in which the base station modulates a carrier signal with a modulation signal, to generate synchronization markers, and transmits the modulated carrier signal. Whereby, a frequency of the modulated carrier signal can be switched between different frequency values.

Abstract: A method for data exchange is provided, whereby a first code is generated by a transponder, which is transmitted to a base station, a first transmission information is generated by the base station by encoding a base station code with a first identification and the first random number code, the first transmission information is transmitted to the transponder and the base station code is extracted by the transponder, a second code is generated by the transponder, which is transmitted to the base station upon an associated request from the base station, whereby before a transmission to the base station the second code is encoded with the extracted base station code, a second encoded transmission information comprising a second identification is generated by the base station with use of the second code and transmitted to the transponder, and at least one memory region of the transponder is released for read and/or write access after the second identification was verified as valid.

Abstract: A method and circuit for wireless data transmission between a base station and one or more transponders is provided in which the base station modulates a carrier signal with a modulation signal and transmits it, in which symbols that are to be transmitted are coded by the base station using sequential delimiters. A value of a particular symbol being determined by the time period between two sequential delimiters, and in which the particular delimiter is generated by changing the modulation signal during a modulation period. Whereby, the modulation signal is preferably a noise signal during the modulation period.

Abstract: One or more transponders are selected by a base station out of a plurality of transponders. For this purpose an identification bit sequence (IB) that is or includes a random number bit sequence (ZB) is made available in the respective transponder and the base station transmits in a bit-by-bit fashion a selection bit sequence (AB) to the transponders. These sequences (IB or ZB) and (AB) are compared bit-by-bit in the respective transponder. The comparing is performed by way of a predeterminable comparing criterion to provide a comparing result in the form of a selection bit to which a bit value is assigned. The selection is then made depending on the bit value of the selection bit of the respective transponder.

Abstract: A security device for a transponder with a kill and/or cloak function is provided. The security device includes a memory device, in which a first, open password is stored, an input, into which a second, secret password is coupled, a cryptologic device, which is connected to the input and generates a checksum from the second password, and a comparison unit, which compares the checksum and the first password and which upon an agreement generates a kill and/or cloak control instruction to activate and/or deactivate a kill and/or cloak mechanism, which can be tapped at an output. A method for configuring a security device and a method for operating a transponder, and a transponder having the security device are also provided.

Abstract: A method for specifying access authorization to at least one memory area of a transponder is provided, in which the memory area is assigned access control information, whereby the access control information comprises at least one configurable master access control information, and write access to the memory area is released at least by a first configuration of the master access control information and write access to the memory area is blocked by a second configuration of the master access control information, whereby in the method the access control information is stored further in the transponder, the access control information is assigned at least one first settable sub-access control information, and the information is scaled by the assignment of the first sub-access control information to the master access control information, so that access authorization specified by the configuration of the master access control information is adapted to at least one additional requirement.

Abstract: A transponder is provided, in particular a passive and/or backscatter-based transponder, for an RFID system, wherein at least one first piece of information can be stored in a first memory area on the transponder that is accessible in clear text only by a read access internal to the transponder, and a second piece of information can be stored in a second memory area that is accessible in clear text through an air interface for read access, and the second piece of information is generated from the first piece of information using an asymmetric encryption method. The invention further relates to an RFID system for wireless data exchange comprising a transponder and a base station, and a method for requesting write and/or read access to a transponder, in particular a passive and/or backscatter-based transponder.

Abstract: A method for wireless data transmission between a base station and a transponder is provided, whereby a message, comprising at least one command and one data sequence, is transmitted by the base station, the message is received and evaluated by the transponder, at least one key is provided in the transponder after receipt of the command and before complete receipt of the message and the key is transmitted to the base station, the key is detected by the base station, and parts of the message, still to be transmitted, and/or subsequent messages are encoded by the base station with the key.

Abstract: In a method for selecting, by a base station, one or more transponders out of a plurality of transponders, selection steps are performed at least at two selection levels or stages. The base station controls all selection steps at the first and second level. The first selection level includes: each transponder generates a random transponder number, the base station generates numbered time slots, each transponder transmits a marker if and when its random transponder number coincides with a time slot number. When a single transponder random number coincides with a time slot number the respective transponder is selected by the base station. If more than one transponder random numbers coincide with a time slot number the second selection procedure is performed at a second selection level as a stochastic or a deterministic or a mixed stochastic-deterministic selection procedure.

Abstract: In known methods for the transmission of data, the data transmission rate is reduced by bit errors especially at high carrier frequencies. In the new method, the data transmission rate can be significantly increased due to the increased reliability in the data transmission by means of the integration of a test signal.

Abstract: A method for access control to at least one memory area of a passive and/or backscatter-based transponder is provided. In the method for access control, depending on an identification selection criterion, a first or at least one second identification within the transponder is activated, the activated identification upon an appropriate request by reader unit is transmitted to said unit, the at least one memory area of the transponder is divided into memory blocks with a settable size, access control information is assigned to a respective memory block, and read and/or write access to a specific memory block is released or blocked depending on the associated access control information and the identification selection criterion.

Abstract: A method for operating a transponder, and a transponder device is disclosed. Data are wirelessly and bidirectionally transmitted between the transponder and a base station through a first interface that is based on an electromagnetic far-field coupling. According to the invention, data are additionally transmitted wirelessly and bidirectionally between the transponder and the base station through at least one second interface that is based on inductive coupling.