Experimental science workflows from projects such as Compact Muon Solenoid (CMS) and Laser Interferometer Gravitational Wave Observatory (LIGO) are characterized by data-intensive computational tasks over large datasets transferred over encrypted channels. The Science DMZ approach to network design favors lossless packet forwarding through a separate isolated network over secure lossy forwarding through stateful packet processors (e.g. firewalls). We propose ScienceSDS, a novel software defined security framework for securely monitoring large-scale science datasets over a software defined networking and network functions virtualization (SDN/NFV) infrastructure.