RidgeRun's gst-crypto plugin makes it easy to encrypt or decrypt content passing through a GStreamer pipeline, it is build directly on top of OpenSSL. gst-crypto will take advantage of any available crypto hardware accelerators. gst-crypto is based on OpenSSL so any encryption technology supported by OpenSSL can be supported by gst-crypto. Currently, only aes-128-cbc cipher is supported.

More information on how to use it on: http://developer.ridgerun.com/wiki/index.php?title=RidgeRun_gst-crypto_GStreamer_Plugin