The application discloses an electronic operating device (100) arranged to protect communication between a consumer application (125) and a network-connected consumer device (300). The operating device protects a command message by signing the command message with a private key obtained from a key storage of the operating device (optionally also encrypting the command message with an encryption key), and sends the protected command message to the network controller (200). The network controller performs the verification of the signature of the command message such that legacy consumer devices without cryptographic capability can be used. The signature ensures that only authorised devices (100) can send commands to the consumer device (300).