An EU official, working under the guidelines of the High Representative and in coordination with the European External Action Service (EEAS), must implement a new security protocol for a crisis operation abroad. The protocol requires the use of a cloud computing platform to share classified documents of type 'RESTREINT UE' with partners from third countries, ensuring data integrity and access traceability. Considering the principles of EU security policy and best practices in cybersecurity, which of the following measures is most appropriate to ensure data protection during this international transfer?