The invention provides a system that preserves the synchronization of the
audio and video presented at a secure conferencing site without
necessitating decryption, decompression, compression, and encryption of
signals at the hub. The presently preferred embodiment of the invention
provides an apparatus and method for synchronizing audio and video in
encrypted videoconferences that comprises a plurality of conference
sites; and a hub for receiving a compressed and encrypted, composite
audio and video signal from each site, for determining a currently active
site, and for transmitting said composite audio and video signal from
said currently active site to all other sites; said hub receiving a
compressed and encrypted audio only signal from each site; wherein said
hub routes all incoming compressed and encrypted audio only signals to
each site.