he's believed to be the mastermind behind some of the terror group's most sophisticated devices. when we talk about devices, this is a whole new world. these are devices that modern methods right now, the best technology out there, actually has no way of detecting. brian todd is "outfront." >> reporter: u.s. intelligence officials have said he could be the most dangerous terrorist america faces. ibrahim al asiri, only 31 years old, master bomb maker for the group al qaeda in the arabian peninsula. he could be involved in the current threat stream. a u.s. intelligence official tells cnn al asiri is the golden goose of that al qaeda affiliate. they're guarded about his communications, determined to protect him. cnn national security analyst peter bergen says that's for good reason. >> the ability to smuggle a potentially undetectable bomb onto a plane or some other location, that's golden for al qaeda. >> reporter: western intelligence officials say al