Abstract: Methods and devices for providing at least one password for a change in state of a device from a first operational state into a second operational state by inputting the password is provided. A number of characters of the password are set in accordance with the duration of the first operating state of the device.

Abstract: A method and an apparatus protect location-related messages which are transmitted from a provider to a plurality of temporally changing recipients and receiver devices in a plurality of localities in each case. The method and apparatus are distinguished by the fact that key certificates for signed messages are issued only in a location-related manner and are thus valid only in a particular defined local environment.

Abstract: A method and an apparatus protect location-related messages which are transmitted from a provider to a plurality of temporally changing recipients and receiver devices in a plurality of localities in each case. The method and apparatus are distinguished by the fact that key certificates for signed messages are issued only in a location-related manner and are thus valid only in a particular defined local environment.

Abstract: A method for monitoring a vicinity using a plurality of acoustic sensors (1, 2, 3, 4), which form a decentralized net (N), in which the sensors (1, 2, 3, 4) communicate with one another, at least in part, wherein the respective sensors (1, 2, 3, 4) register acoustic signals based on noises in the vicinity, and reprocess the registered signals to conduct a situation recognition. According to the method, a respective sensor (1, 2, 3, 4) of at least some of the sensors (1, 2, 3, 4) accesses, via the decentralized net (N), the registered and/or reprocessed signals of one, or several, adjacent sensors (1, 2, 3, 4), and takes these signals into account for the situation recognition, wherein an adjacent sensor (1, 2, 3, 4) registers signals, which, at least in part, are based on the same noises as the ones registered by the respective sensor.