"There is unfortunately one less straightforward way that attackers can access another module’s memory—side-channel attacks like Spectre. OS processes attempt to provide something called time protection, and this helps protect against these attacks. Unfortunately, CPUs and OSes don’t offer finer-than-process granularity time protection features."
"[snip] Making a shift to nanoprocesses here would take careful analysis."
"But there are lots of situations where timing protection isn’t needed, or where people aren’t using processes at all right now. These are good candidates for nanoprocesses."
"Plus, as CPUs evolve to provide cheaper time protection features, WebAssembly nanoprocesses will be in a good position to quickly take advantage of these features, at which point you won’t need to use OS processes for this."