Secure beacons

A computer-implemented method for securing a beacon signal in a network comprising a transmitter for broadcasting the beacon signal and one or more receivers for receiving the beacon signal, wherein the beacon signal comprises a data packet, the data packet including a payload, wherein the payload comprises a first field containing broadcast information from the transmitter, a second field for storing authentication information, and a sequence number field for storing a sequence number, wherein the sequence number is incremented for each new beacon signal transmitted by the transmitter, the method comprising:

• computing, using a secret key, a message authentication code over at least a part of the payload;
• extracting a predefined number of bytes from the message authentication code to obtain the authentication information, the predefined number of bytes being equal to or less than the length of the second field;
• and
• encrypting at least part of the first field using a symmetric cipher which takes as parameter the secret key and a nonce, wherein the nonce is based on the authentication information and the sequence number, the encrypting resulting in an encrypted first field, wherein the resulting secure beacon signal comprises the data packet, wherein the payload comprises the encrypted first field and the second field contains the authentication information.