Exchange Participants (EPs) should note that a new OCG-C RSA public key has been implemented in the testing environment since 8th August 2023. HKEX will renew the key on the production environment, allowing a transitional period for both old and new keys to be used for encryption. EPs must update the key for OCG-C Trading and Drop-Copy sessions. The new key will be distributed via the Electronic Communication Platform (ECP). EPs should participate in one of the three mandatory Connectivity Sessions to test the new key before using it in the production environment. Registration is required by 1st September 2023. Details will be provided to registered EPs.