Abstract The total increase in the use of mobile devices inevitably leads to an increase in the number of different security threats. The cryptographic device described in this article provides a secure (encrypted) transmission of data. It alerts the user if the crypto headset at the opposite end of the link is not trusted, thus extending the offending model (i.e. a list of the potential opportunities of the offender) to the possibility of substituting one of the encrypting devices. All functions for encryption and decryption are enclosed in a separate unit that connects to the phone via Bluetooth. The crypto headset specifications were compared with the closest analogues and ensures a higher level of security for each group of consumers: the corporate sector, government agencies, and individual users.