This document summarizes past, present, and future work on multimedia security within ITU-T Study Group 16. It discusses security standards and profiles for secure IP telephony (H.323/H.235), media gateway decomposition (H.248), audio/video conferencing (H.320), and data conferencing (T.120). Ongoing and planned work items are outlined, including investigating signaling confidentiality, video encryption, mobility security, and secure emergency telecommunications services.