A hearing device comprising a processing unit configured to compensate for hearing loss of a user of the hearing device; an interface ; and a memory unit , wherein the memory unit has stored therein: a first primary certificate comprising a first primary hearing device identifier (HD_ID_1_1) and one or more keysets including a first primary keyset (KEY_SET_1_1); and a second primary certificate comprising a second primary hearing device identifier (HD_ID_2_1) and second key data for third-party control of the hearing device, the second key data comprising one or more second keysets including a second primary keyset (KEY_SET_2_1), wherein the processing unit is configured to: verify the second primary certificate ; in accordance with a successful verification of the second primary certificate, communicate with a third-party entity based on the second key data, characterized in that to communicate with the third-party entity based on the second key data comprises to apply a third-party operating system in the processing unit, wherein to apply the-third party operating system in the processing unit comprises to install and run the third-party operating system in the processing unit. a processing unit configured to compensate for hearing loss of a user of the hearing device; an interface ; and a memory unit , wherein the memory unit has stored therein: a first primary certificate comprising a first primary hearing device identifier (HD_ID_1_1) and one or more keysets including a first primary keyset (KEY_SET_1_1); and a second primary certificate comprising a second primary hearing device identifier (HD_ID_2_1) and second key data for third-party control of the hearing device, the second key data comprising one or more second keysets including a second primary keyset (KEY_SET_2_1), a first primary certificate comprising a first primary hearing device identifier (HD_ID_1_1) and one or more keysets including a first primary keyset (KEY_SET_1_1); and a second primary certificate comprising a second primary hearing device identifier (HD_ID_2_1) and second key data for third-party control of the hearing device, the second key data comprising one or more second keysets including a second primary keyset (KEY_SET_2_1), wherein the processing unit is configured to: verify the second primary certificate ; in accordance with a successful verification of the second primary certificate, communicate with a third-party entity based on the second key data, characterized in that to communicate with the third-party entity based on the second key data comprises to apply a third-party operating system in the processing unit, wherein to apply the-third party operating system in the processing unit comprises to install and run the third-party operating system in the processing unit. verify the second primary certificate ; in accordance with a successful verification of the second primary certificate, communicate with a third-party entity based on the second key data, characterized in that to communicate with the third-party entity based on the second key data comprises to apply a third-party operating system in the processing unit, wherein to apply the-third party operating system in the processing unit comprises to install and run the third-party operating system in the processing unit. <EOS>