A Security Scheme for Dependable Key Insertion in Mobile Embedded Devices

Algorithm 3

Direct flashing protocol (with online connection to OEM).

Requirements

(i) UD has knowledge of VK_OEM

(ii) OEM has ensured, that the legal owner OWN of UD has commissioned the flashing procedure

Protocol

Step  1: For a new TRK_new to be flashed OEM reads out the respective certified

   verification key 𝚂𝚒𝚐_{SK𝚃𝚁𝙺𝙼}(VK_{𝚃𝚁𝙺new}) and verifies that VK_TRKM is in

   the internal database of trusted transponder manufacturers.

Step  2: OEM contacts UD and is authenticated using a PKC authentication protocol.

   UD sends 𝚂𝚒𝚐_SK𝚄𝙳(VK_𝚄𝙳) to OEM.

Step  3: OEM verifies that V(𝚂𝚒𝚐_SK𝚄𝙳(VK_𝚄𝙳),VK_𝚄𝙳)=^!1

Step  4: OEM sends 𝚂𝚒𝚐_{SK𝙾𝙴𝙼}(VK_{𝚃𝚁𝙺new},VK_𝚄𝙳) to UD.

Step  5: UD verifies that V(𝚂𝚒𝚐_{SK𝙾𝙴𝙼}(VK_{𝚃𝚁𝙺new},VK^′_𝚄𝙳),VK_𝙾𝙴𝙼)=^!1.

Step  6: UD verifies that VK^′!_𝚄𝙳=VK_𝚄𝙳. Then the new transponder 𝚃𝚁𝙺_new can be activated.

   The protocol is completed by sending a DONE-message to OEM.