It is possible to map entire structure into a signature. For example mimicking other form of structure with your cells and even replicate internal functions, like human with photosynthesis (the other word for it is shape-shifting), and likely more efficient than nanotech. Or filter out certain particle since its signature are different from other, for say producing pure water. Such a shame that magic was lost after the rise of Catholics. But there are even Christian magic (that many priests know quite well), and definitely ones of Judaism.