Method and device for installing certificate on basis of encryption and decryption of contract certificate private key

An apparatus for installing a certificate in an electric vehicle based on encryption and decryption of a contract certificate private key, the apparatus comprising:

• a processor;
• a memory storing instructions executable by the processor;
• and
• a communication interface connected to the processor and communicating with an external apparatus through a network,
• wherein the processor is configured to:
• transmit, to a secondary actor, a certificate installation request message requesting a new contract certificate;
• and
• receive, from the secondary actor, a certificate installation response message signed with a private key associated with a leaf certificate of a certificate provisioning service,
• wherein the certificate installation response message includes a contract certificate data packet including a signed installation data element, the signed installation data element includes a contract certificate chain element and an encrypted private key element, and the encrypted private key element stores a private key belonging to the new contract certificate encrypted for an electric vehicle communication controller without a trusted platform module,
• wherein the private key belonging to the new contract certificate is encrypted using an advanced encryption standard (AES)-Galois/counter mode (GCM) based on an encryption key which is generated from a public key of the manufacturer provisioning certificate and the private key of the secondary actor through elliptic-curve Diffie-Hellman (ECDH) protocol, and the private key encrypted using the AES-GCM is included as a 521-bit or 448-bit ciphertext in an encrypted private key field following a 96-bit or 128-bit initialization vector in the contract certificate data packet, and
• wherein the initialization vector is included in the encrypted contract private key structure and is used as input to the AES-GCM decryption process together with the encryption key derived via ECDH, to decrypt the encrypted private key.

An apparatus for installing a certificate in an electric vehicle based on encryption and decryption of a contract certificate private key, the apparatus comprising:

• a processor;
• a memory storing instructions executable by the processor;
• and
• a communication interface connected to the processor and communicating with an external apparatus through a network,
• wherein the processor is configured to:
• receive, from an electric vehicle communication controller;
• a certificate installation request message requesting a new contract certificate;
• and
• transmit, to the electric vehicle communication controller, a certificate installation response message signed with a private key associated with a leaf certificate of a certificate provisioning service,
• wherein the certificate installation response message includes a contract certificate data packet including a signed installation data element, the signed installation data element includes a contract certificate chain element and an encrypted private key element, and the encrypted private key element stores a private key belonging to the new contract certificate encrypted for the electric vehicle communication controller without a trusted platform module,
• wherein the private key belonging to the new contract certificate is encrypted using an advanced encryption standard (AES)-Galois/counter mode (GCM) based on an encryption key which is generated from a public key of the manufacturer provisioning certificate and the private key through elliptic-curve Diffie-Hellman (ECDH) protocol, and the private key encrypted using the AES-GCM is included as a 521-bit or 448-bit ciphertext following a 96-bit or 128-bit initialization vector in the contract certificate data packet, and
• wherein the initialization vector is included in the encrypted contract private key structure and is used as input to the AES-GCM decryption process together with the encryption key derived via ECDH, to decrypt the encrypted private key.