Hearing instrument with an authentication protocol

A method of communicating a message, comprising:

• encoding a part of the message for broadcasting;
• encrypting the part of the message with a first key, wherein the part of the message that is encrypted with the first key comprises information to be conveyed to a user;
• encrypting the first key with a second key to obtain an encrypted first key;
• broadcasting the encrypted first key for reception by a device that is configured for worn by the user;
• and
• broadcasting the encrypted part of the message for reception by the device, wherein the device is configured for receiving the encrypted first key and the encrypted part of the message, decrypting the first key with a third key, decrypting the part of the message with the first key, and converting the part of the message into an acoustic signal for transmission towards an eardrum of a human;
• wherein the second key has a value that is different from a value of the third key;
• and
• wherein the message comprises (1) a first payload broadcasted with the encrypted first key, and (2) a second payload broadcasted without the encrypted first key.

A broadcasting system comprising:

• an encoder configured for encoding a part of a message for broadcasting;
• an encryption unit configured for encrypting the part of the message with a first key, and encrypting the first key with a second key to obtain an encrypted first key, wherein the part of the message encrypted by the encryption unit comprises information to be conveyed to a user;
• and
• a transmitter configured for broadcasting a signal having the encrypted first key and the encrypted part of the message for reception by a hearing instrument that is configured for worn by the user;
• wherein the hearing instrument comprises a radio for reception of the signal having the message and the encrypted first key, an authenticator configured for authentication of the message by decrypting the first key with a third key, and decrypting the part of the message with the first key, and a processing unit configured for converting the message into an acoustic signal for transmission towards an eardrum of the user of the hearing instrument;
• wherein the second key has a value that is different from a value of the third key;
• and
• wherein the message comprises (1) a first payload transmitted with the encrypted first key, and (2) a second payload broadcasted without the encrypted first key.