Abstract: An electronic apparatus has a protection device which includes a random number generator for producing a random number unique to the electronic apparatus. The random number is stored as a personality data in a memory when the electronic apparatus is switched on for the first time. Subsequently, a comparator compares the random number with the personality data stored in the memory and prevents operation of the electronic apparatus device and/or memory access when the comparison result indicates that the random number and personality data are different. The random number generator is formed by a voltage divider of resistors having large tolerances and/or being chosen randomly, where the voltage divider output is converted to a digital value.

Abstract: The invention relates to an electronic apparatus whose power is supplied by a battery (11) having a memory (32) which contains electrically erasable data (32a) and a supply voltage detection device (37) for detecting a variation of the supply voltage (Vbat). The invention notably has for its object to provide a detection device (37) which is capable of instantaneously detecting various voltage levels to cut off the power supply (Vbat) without the contents of the memory (32) being changed and capable of indicating the charging level of a battery (11) or an overload. The invention may be used in portable telephones and other electronic equipment whose power is supplied by a power supply battery.

Abstract: A telephone is disclosed having a memory which stores a full menu and a customization unit which customizes the full menu to form a custom menu. The customization unit includes a masking device which masks selected items of the full menu to form the custom menu. A screen displays the custom menu. A keyboard has a key which manually controls the masking device. Further, a counter counts the number of times items of the full menu are accessed by a user to determine the selected items. In particular, the selected items are the least frequently accessed elements of the menu by the user. The counter controls the masking device to mask the selected items.

Abstract: The invention relates to an anti-theft method for a vehicle. In accordance with the invention, a code word (K1) chosen by the user, and the serial number ESN or IMEI of the telephone (K2) are stored in a fastener element (4) connected to the vehicle (5) and serving as a cradle for the portable telephone (1). Before starting, the user is to put his telephone in its place in the fastener element. The telephone automatically verifies whether its serial number ESN or IMEI is identical with the one that is stored in the fastener element. In that case, the starter means of the vehicle are unblocked so that the action of the ignition key makes a start possible. In the opposite case, the starter means remain blocked.