I can't really say that I support this idea.
Okay, lemme just point out that this has a total of zero uses in singleplayer mode, considering that there are no mobs that steal items from chests, nor will there ever be, considering that mob would be annoying and trollish.
I can't really see a use for this in multiplayer either, though.
If you decided to use this for the sake of keeping items safe from other players: You can't get bedrock in survival mode, and you can mine obsidian with a diamond pickaxe, so they would still be able to get at your stuff, provided you aren't using a block protection plugin. (Which removes the need for having any sort of Vanilla chest protection, anyway.)
Also, I'd think I'd rather just let the greifer get my stuff. He probably deserves his reward, and I may or may not be able to steal it back at some point.