Abstract: The invention relates to an RFID tag, which comprises a receiving means, a first and a second verification means, and a transmitting means. The receiving means is designed to receive a challenge message sent by an RFID reading device. Said challenge message comprises a challenge data set, which has a digital certificate issued for the RFID reading device by a certification authority and signed by means of a private key of the certification authority and which has a request message, and a digital signature at least of the request message, which digital signature is generated by means of a private key of the RFID reading device. The first verification means is designed to verify the digital certificate by means of a public key of the certification authority. The second verification means is designed to verify the digital signature by means of a public key of the RFID reading device.

Abstract: The invention relates to an RFID tag, which comprises a receiving means, a first and a second verification means, and a transmitting means. The receiving means is designed to receive a challenge message sent by an RFID reading device. Said challenge message comprises a challenge data set, which has a digital certificate issued for the RFID reading device by a certification authority and signed by means of a private key of the certification authority and which has a request message, and a digital signature at least of the request message, which digital signature is generated by means of a private key of the RFID reading device. The first verification means is designed to verify the digital certificate by means of a public key of the certification authority. The second verification means is designed to verify the digital signature by means of a public key of the RFID reading device.

Abstract: A tachograph and a toll onboard unit as communication partners, which each have a data interface for a data communication via a vehicle data bus to which the communication partners are coupled. The tachograph and/or the toll onboard unit are implemented as a transmitter of data to ascertain a cryptographic check value as a function of user data, which are to be transmitted to the communication partner, and to transmit the cryptographic check value in addition to the user data to the communication partner. The toll onboard unit or the tachograph, respectively, as a receiver of data, is implemented to receive user data and the cryptographic check value associated with the user data from the communication partner and to check the received user data for corruption as a function of the received cryptographic check value.

Abstract: A method for verifying an electronic signature is described including determining a residue class given by the signature; determining an integer having the residue class; determining a field element of a finite field such that the field element corresponds to the integer according to a predetermined mapping of the finite field to the set of integers; determining whether the field element fulfills a predetermined criterion and deciding whether the signature is valid based on whether the field element fulfills the predetermined criterion.

Abstract: A method for verifying an electronic signature is described including determining a residue class given by the signature; determining an integer having the residue class; determining a field element of a finite field such that the field element corresponds to the integer according to a predetermined mapping of the finite field to the set of integers; determining whether the field element fulfills a predetermined criterion and deciding whether the signature is valid based on whether the field element fulfills the predetermined criterion.

Abstract: In a data transmission method for a tachograph system, digital messages are transmitted between a speed transmitter (MS) and a recording unit (RU). The digital messages contain a pair of keys including a public key (KMP, KRP) and a private key (KMS, KRS), as well as a certificate (ZM, ZR) derived from the respective pair of keys. The public keys (KMP, KRP) and the certificates (ZM, ZR) are mutually verified between the recording unit (RU) and the speed transmitter (MS). If the verification is positive, the speed transmitter (MS) detects sensor data, and a digital message is generated therefrom. In addition, the speed transmitter (MS) generates authentication data for the message in accordance with the pair of keys (KMP, KMS) thereof. The message and the authentication data are transmitted to the recording unit and are processed there in accordance with a validity of the authentication data verified by the recording unit (RU).

Abstract: An authentication method authenticates between subscribers of a communications system using an asymmetric elliptic curve encryption algorithm. The method involves providing a first and at least one second subscriber having a first or second secret key known only to the respective subscriber and a public key; authenticating an inquiry transmitted by the first subscriber with respect to the validity of the first certificate contained therein and associated with the first subscriber; calculating the response of the second subscriber associated with the inquiry; randomized encryption of the calculated response and a second certificate associated with the second subscriber using the public key; decryption and authentication of the response transmitted by the second subscriber with respect to the validity of the second certificate contained therein.

Abstract: An encryption part or a decryption part of an encryption/decryption apparatus or a part common to both parts is used both for encryption and decryption of a datum to be stored and the encrypted memory content and for the generation of the address-individual key and the address-dependent key, respectively.

Abstract: The invention relates to an encoding method for identifying a subsequential manipulation of a counter meter reading consisting, when the counter reading is increased or decreased, in activating the computation of a new encoded meter reading and in calculating a new encoded meter reading by applying a forward chain one-way function to the encoded meter reading, wherein a complex variable domain of said forward chain one-way function is included into the antecedent domain thereof.

Abstract: In a data transmission method for a tachograph system, digital messages are transmitted between a speed transmitter (MS) and a recording unit (RU). The digital messages contain a pair of keys including a public key (KMP, KRP) and a private key (KMS, KRS), as well as a certificate (ZM, ZR) derived from the respective pair of keys. The public keys (KMP, KRP) and the certificates (ZM, ZR) are mutually verified between the recording unit (RU) and the speed transmitter (MS). If the verification is positive, the speed transmitter (MS) detects sensor data, and a digital message is generated therefrom. In addition, the speed transmitter (MS) generates authentication data for the message in accordance with the pair of keys (KMP, KMS) thereof. The message and the authentication data are transmitted to the recording unit and are processed there in accordance with a validity of the authentication data verified by the recording unit (RU).

Abstract: A tachograph and a toll onboard unit as communication partners, which each have a data interface for a data communication via a vehicle data bus to which the communication partners are coupled. The tachograph and/or the toll onboard unit are implemented as a transmitter of data to ascertain a cryptographic check value as a function of user data, which are to be transmitted to the communication partner, and to transmit the cryptographic check value in addition to the user data to the communication partner. The toll onboard unit or the tachograph, respectively, as a receiver of data, is implemented to receive user data and the cryptographic check value associated with the user data from the communication partner and to check the received user data for corruption as a function of the received cryptographic check value.

Abstract: An authentication method authenticates between subscribers of a communications system using an asymmetric elliptic curve encryption algorithm. The method involves providing a first and at least one second subscriber having a first or second secret key known only to the respective subscriber and a public key; authenticating an inquiry transmitted by the first subscriber with respect to the validity of the first certificate contained therein and associated with the first subscriber; calculating the response of the second subscriber associated with the inquiry; randomized encryption of the calculated response and a second certificate associated with the second subscriber using the public key; decryption and authentication of the response transmitted by the second subscriber with respect to the validity of the second certificate contained therein.

Abstract: A method and a configuration are described for mutual authentication of two data processing units. The mutual authentication of two data processing units is normally carried out in two separate authentication processes, which are carried out successively. A challenge and response method is normally used. For this purpose, a first challenge is sent from a first data processing unit to a second data processing unit, which transmits a first response back. A second response is produced by the first data processing unit, and is transmitted to the second data processing unit.

Abstract: A method for authentication and identification uses different keys for the prover and the verifier, but on the other hand dispenses with the utilization of long number modulo arithmetic by the use of simple basic components such as, for example, arithmetic operations in finite bodies GF(2n). A private key is stored in the prover, so that the latter can receive, in encrypted form, data elements generated as random elements and can itself utilize them again as key for an authentication method of a data set to be transmitted. The verifier receives the authenticator thus formed and checks it. If the data set is generated by the verifier and transmitted to the prover, then this method can serve for the identification of the prover. The method is particularly advantageous in the area of smart cards, since there the required space in the hardware implementation can be considerably reduced.

Abstract: An encryption part or a decryption part of an encryption/decryption apparatus or a part common to both parts is used both for encryption and decryption of a datum to be stored and the encrypted memory content and for the generation of the address-individual key and the address-dependent key, respectively.

Abstract: Applying both an encryption and also a decryption algorithm, which is inverse to the encryption algorithm, as an encryption definition to thereby enable the use of an encryption unit and a decryption unit of an encryption/decryption device simultaneously, i.e. temporally overlapping, in an encryption process when a part of the data to be encrypted is supplied to the encryption unit while the other part is supplied to the decryption unit. The result is encrypted data or is a cipher text, respectively, whose parts are only “encrypted” in a different way. During decryption, it only has to be guaranteed by suitable regulations that those parts which were encrypted by the encrypted unit are again decrypted by the decryption unit, while the other parts which were “encrypted” by the decryption unit are “decrypted” by the encryption unit.

Abstract: In the case of cryptographic processing with the aid of an elliptic curve, parameters of the elliptic curve are stored in a memory of a computer. These parameters are each of substantial length. The elliptic curve is transformed in order to shorten at least one parameter significantly in length and to ensure that the high security level is unchanged in the process. One parameter is preferably shortened to 1, ?1, 2 or ?2 with the aid of an algorithm, whereas the other parameters have a length of several 100 bits. The shortening of even one parameter is clearly reflected in the case of devices which have little memory space.

Abstract: A method for authentication and identification uses different keys for the prover and the verifier, but on the other hand dispenses with the utilization of long number modulo arithmetic by the use of simple basic components such as, for example, arithmetic operations in finite bodies GF(2n). A private key is stored in the prover, so that the latter can receive, in encrypted form, data elements generated as random elements and can itself utilize them again as key for an authentication method of a data set to be transmitted. The verifier receives the authenticator thus formed and checks it. If the data set is generated by the verifier and transmitted to the prover, then this method can serve for the identification of the prover. The method is particularly advantageous in the area of smart cards, since there the required space in the hardware implementation can be considerably reduced.

Abstract: A circuit configuration includes at least one nonvolatile, electrically erasable and writable memory area. Each memory area is assigned a nonvolatile, electrically writable and erasable flag memory, which is connected through an address line, a programming line and an authentication line to the assigned memory area, a programming voltage source and a data verification circuit. In the event of an alteration in the content of a memory area, the state of the associated flag memory is changed and, after verification of the programmed memory area content, the flag memory is returned to its basic state.

Abstract: A method and a configuration are described for mutual authentication of two data processing units. The mutual authentication of two data processing units is normally carried out in two separate authentication processes, which are carried out successively. A challenge and response method is normally used. For this purpose, a first challenge is sent from a first data processing unit to a second data processing unit, which transmits a first response back. A second response is produced by the first data processing unit, and is transmitted to the second data processing unit.