Not necessarily, for example a few MSBs of Y, Cr, and Cb DC and AC could be encoded with the current JFIF markers and new ones used the for rest in an encrypted

Not necessarily, for example a few MSBs of Y, Cr, and Cb DC and AC could be encoded with the current JFIF markers and new ones used the for rest in an encrypted representation. In that manner a current decoder could produce a lower fidelity version still: http://www.jpeg.org/items/20150910_privacy_security_summary.html http://www.jpeg.org/items/20150910_privacy_security_summary....