An EU official assigned to a mission of the Common Foreign and Security Policy (CFSP) abroad must send a confidential report that contains personal data of third-country citizens and details about security operations. The report must be transmitted securely to the EU headquarters and then shared with the diplomatic representations of other Member States. Considering the EU security framework and data protection obligations, what is the most robust approach to ensure the security of these data during storage, processing, and transmission without violating data protection principles?