Method and device for providing an authorization to access a vehicle

A method for providing an authorization to access a vehicle by means of a portable electronic key configured for handling wireless signal exchanges, the vehicle comprising at least two transceivers distributed at different locations, each of said transceivers being configured to emit a first signal and to receive a second signal from the portable electronic key, said authorization being subject to a successful completion of a control procedure comprising:

• determining, for each of said first signals, a first piece of information on the basis of at least one strength measurement of said first signal at the portable electronic key,
• determining, for said second signal, a second piece of information on the basis of at least one strength measurement of the second signal at each of the transceivers, and
• checking whether the first pieces of information are consistent with the second pieces of information and, if so, initiating or granting access to an unlocking procedure configured to provide said authorization,
• wherein the checking whether the first pieces of information are consistent with the second pieces of information further comprises:
• forming a first orderly sequence of data by ordering the first pieces of information,
• forming a second orderly sequence of data by ordering the second pieces of information, and
• checking the consistency between the first and second orderly sequences of data.