Suppose the NSA through legal means, or a malware group through illegal means has access to enormous computational resources via a backdoor into all Microsoft Windows machines (or some significant subset of windows machines).
What percentage of https traffic could be reliably decrypted through brute force?
In other words, are there enough conventional computer chips in the world that, if networked together could break cryptography?
Similarly, could a popular app like facebook or WhatsApp utilize the client cpu to give them powers they wouldn't otherwise have with their own resources? Does this happen?