Method and apparatus for connection between electronic devices

An electronic device comprising:

• a wireless communication unit configured to perform wireless communication with an external device;
• a memory;
• and
• a processor connected to the wireless communication unit and the memory,
• wherein the processor is configured to:
• register the external device as a companion device of the electronic device based on first authentication information of the external device,
• establish a communication connection with the external device through the wireless communication unit,
• transmit an authentication request to the external device in response to the communication connection,
• receive second authentication information from the external device in response to the authentication request,
• identify a signature for the received second authentication information, and
• process authentication of the electronic device through the external device when the signature of the second authentication information is identified,
• wherein the processor is further configured to:
• make a request for registering a public key infrastructure (PKI) in the external device in response to a symmetric registration request corresponding to the external device,
• receive the first authentication information including attestation and a user authenticator from the external device in response to the request for registering the PKI,
• identify a signature of the attestation based on a root certificate stored in the electronic device in response to the reception of the first authentication information,
• identify a signature of the user authenticator based on the identified attestation,
• generate and store a symmetric key for symmetric-key authentication of the external device based on the identification of the signature of the first authentication information, and
• map and store a PKI authentication key and the symmetric key, and wherein the symmetric key is configured not to be exposed to the external device.