West: Post-Spectre web development

Mike West has posted a detailed explorationof what is really required to protect sensitive information in webapplications from speculative-execution exploits. "Spectre-likeside-channel attacks inexorably lead to a model in which active web content(JavaScript, WASM, probably CSS if we tried hard enough, and so on) canread any and all data which has entered the address space of the processwhich hosts it. While this has deep implications for user agentimplementations' internal hardening strategies (stack canaries, ASLR, etc),here we'll remain focused on the core implication at the web platformlevel, which is both simple and profound: any data which flows into aprocess hosting a given origin is legible to that origin. We must designaccordingly."