Abstract: A method of protecting a microcomputer system against manipulation of data stored in a memory assembly of the microcomputer system is provided. The method may protect, for example, a control program stored in the memory assembly of a motor vehicle control device. To secure and reliably protect the microcomputer system against manipulation of the data, the data is stored in the memory assembly marked or encrypted using an asymmetrical encryption method. The data may, for example, be encrypted outside the microcomputer system using an encryption algorithm and a private key, which is accessible to only a limited group of persons. The data may be decrypted in the microcomputer system using a decryption algorithm and a freely accessible public key.

Abstract: A method of operating a microcomputer system in which at least part of a memory system of the microcomputer system is checked for manipulation of data stored in the memory system. Measures to prevent processing of the data in the microcomputer system are performed as a function of the result of the check, if the measures are activated. The measures are activated or deactivated as a function of the content of a read-only memory of the microcomputer system. To increase the effectiveness and reliability of a manipulation or tuning protection of the data, a code word is stored in the data, which is checked while the microcomputer system is in operation, and the measures are activated or deactivated as a function of the result of the check of the code word stored in the data.

Abstract: The invention relates to a method for operating a GSM mobile radio system, according to which at least one transmitter, which is allocated to a reference time generator, emits a signal including information concerning a reference time. The signal including the aforementioned information is received by the base stations. Each base station then synchronizes time slots of communications channels with reference to the reference time, said channels being made available via a radio interface between each respective base station and its allocated subscriber station.

Abstract: A tampering-protected microprocessor system includes a microprocessor, an internal write/read memory integrated with the microprocessor into a common module, and a second memory in which at least a portion of an operating program to be executed by the microprocessor is stored. At least one procedure of the operating program which is indispensable for the function of the microprocessor system is stored in encrypted form in the external memory. The operating program includes a decryption procedure which decrypts each encrypted procedure of the operating program and stores it in the internal write/read memory. The indispensable procedure, in order to function properly, requires a successful execution of an integrity test procedure which tests the integrity of at least a portion of the operating program.

Abstract: Data are transmitted through a radio interface in a GSM mobile radio system. The transmission side performs a continuous phase modulation of the transmission signals for the data to be transmitted. A bandwidth is used which is narrower than that used during a Gaussian minimum shift keying modulation with a modulation bandwidth BT equal to 0.3 so that the radio interface gives right of access on at least one channel with a reduced bandwidth. On the reception side, data detection is carried out without any discrimination between channels with different bandwidths. This enables substantially increased capacity of mobile radiotelephone networks and support for indoor and asymmetrical data transmission applications.

Abstract: A method of protecting a microcomputer system against manipulation of data stored in a memory assembly of the microcomputer system is provided. The method may protect, for example, a control program stored in the memory assembly of a motor vehicle control device. To secure and reliably protect the microcomputer system against manipulation of the data, the data is stored in the memory assembly marked or encrypted using an asymmetrical encryption method. The data may, for example, be encrypted outside the microcomputer system using an encryption algorithm and a private key, which is accessible to only a limited group of persons. The data may be decrypted in the microcomputer system using a decryption algorithm and a freely accessible public key.

Abstract: A method of operating a microcomputer system in which at least part of a memory system of the microcomputer system is checked for manipulation of data stored in the memory system. Measures to prevent processing of the data in the microcomputer system are performed as a function of the result of the check, if the measures are activated. The measures are activated or deactivated as a function of the content of a read-only memory of the microcomputer system. To increase the effectiveness and reliability of a manipulation or tuning protection of the data, a code word is stored in the data, which is checked while the microcomputer system is in operation, and the measures are activated or deactivated as a function of the result of the check of the code word stored in the data.