DWGSOFT DWGLock - Version 2.81 A powerful and fast dwg tools, Protecting drawing file,Keep others from modifying/copying your design. DWGLockis a stand-alone application, no AutoCAD required;Supports AutoCAD R2.9 thru 2009 drawings.Features:Powerful encryption capabilities, secure Maximizesecurity for the entities in the drawing, they can notcopy nor change it.Say No to any arbitrary use of yourdesigns; Recipients can open up to view protected drawingwithout any inconvenience, they can even add lines,markup.Preserve or discard their comments, it's all upto you!The drawing owner can lock or unlock the source drawingwith a password;Batch encrypt/un-encrypt many files or folders just inone go.