Well there are many forms of masking, from tape to software security. embedded code is a form of masking. I am not sure of which application is best suited for the name "Masking" but I know there are many possibilites. Using Google and doing a search on the word "masking" I get 588,000 results. So That tells me that this name has potential. The .us Tld is a major drawback at this time because of being fairly new and unproven as an acceptable extension. Time will tell, but I believe ".us" will be common place in the next few years. Pure speculation on my behalf.
Don't forget your gasmask, duct Tape and plastic, for all your "Masking" needs.