The only part of the theory we know as of now is that it is the heat that causes evaporation. There can be much more to know about the same in future. So, is the case with the facts and believes related to cyber security. We can never predict the upcoming threats and the sustainability of the security measures which are the best in today`s date.
There are threats we know and there are threats we know that we do not know about and then there are threats that are yet unknown about cyber security. Had such threats been known to us at the time of inception of the computer world, the human race would have restricted its exposure to it.