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    Sounds suspiciously like something new is under embargo.

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      A requirement for TCSEC certification (1983) at higher levels was periods processing. Moving from one, security label to another required the TCB (eg OS kernel) to flush out any shared resources, esp in CPU, that previous label used. This was to prevent potential leaks from a high-secrecy to low-secrecy process and/or potential attacks from a low-integrity to a high-integrity process. One effect this had was to make high-security kernels appear too slow to be marketable, esp on older hardware. Timing channel mitigations, which might not even work, impacted the rest of the stack both in performance penalties and rewrites of legacy code to use intentionally-imprecise timers.

      The CPU attacks got Linux systems to start doing responding to the threat those decades-old systems tried to address. They’ve been clever defenses in comparison trying to balance security vs performance hits. Now, it looks like they’re getting plain-old, periods processing with the performance hit like before. Wonder what effects this will have in the market. Having safer languages, multicores, GPU’s, and FPGA’s available gives opportunities to mitigate the negative impact more than before.

      “and as such the documentation continues to refer to this capability as something for “paranoid” users. “

      Linux itself is probably not a good choice for “paranoid” users. ;) If it must be complex, they might want something like OpenBSD, HardenedBSD, seL4 + Genode w/ Linux VM’s, or INTEGRITY-178B with Linux VM’s.

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        aka:

        How to make your system significantly slower one more time, without any visible gain for the user apart from virtual “security” concept, as it seems like Electron apps and web-ization of desktop experience isn’t enough for that

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          more like “The shoe has dropped on x86’s architectural compromises and mistakes; the free ride for performance at the expense of security has ended”

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            At this particular point of the history of mankind, regular personal computer users doesn’t care about their own machine’s security at all. Instead, they get angry on yet another patch which “slows down” their machine. And while it was mythical and hard to prove in the past, it’s real now and quite “validates” their standpoint to not update or even rollback anything they use to older version because it runs faster.

            So we get the opposite effect with each exposed vulernability.

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              At this particular point of the history of mankind, regular personal computer users doesn’t care about their own machine’s security at all.

              I think we live in different realities. I still remember the Blaster/CodeRED worms and how they took off. And the public panic. That’s why the computing scene has changed to become increasingly locked down and less open over my lifetime. Things my father would tell me about early computing seem unthinkable now, yet they were commonplace once upon a time.

              Instead, they get angry on yet another patch which “slows down” their machine.

              They already do that, even to systems that have not had a change. Perceptions are shaped by emotions and when emotions run hot, people shape their perceptions accordingly.

              The only people who really are going to “feel” this additional security “fix” (more like papering over) are kernel land people and those who depend on context switch overhead not being immense, like web services (where I work). If you can ensure you’re on dedicated hardware, you don’t need these fixes are you probably have a relatively locked down environment. However multitenant hardware like how AWS does business means if it is possible to escape Xen and touch data that isn’t yours, it’s catastrophic. An enterprise company can buy more nodes. They can’t buy back leaked secrets.

              The fundamental vulnerabilities are from the speed race of the late 90s and the processor wars favoring every and any dirty trick to beat the competition. Turns out that sacrificed more than integrity, it sacrificed security in a world where security has become more paramount. And now we’re addicted to fast speeds and security, a difficult and expensive combination