Why some of my talks and papers aren't available for download

Due to security and confidentiality restrictions, and also as a consequence of US laws restricting export of certain kinds of information (ITAR), I have to go through a fairly lengthy procedure to get permission to release any work-related information publicly.

Any papers in refereed journals and conferences have to have clearance before I can submit them, so they will typically always be available for download. However, some presentations to closed audiences can not be released (though I will typically attempt to obtain clearance to do so where possible), so please accept my apologies for that -- it's not my choice or within my power to influence this.