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0 pointsdfrage6y ago0 comments

https://en.wikipedia.org/wiki/Time-sharing

Time sharing was very big in the 1970s, and non-OS/VM methods of sharing mainframes for batch processing were also big at times I'm less sure of.

Inviting complete randoms to routinely run untrusted code in your own security domain, as we do with browsers, that's "new". And thus the popularity of NoScript and uMatrix.

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nine_k6y ago

Indeed! Though time-sharing was more like a terminal server, or shared hosting, while OS/VM was more like a modern VM host.

It's interesting though why cross-process data exfiltration based on speculative execution was not tried with any success in the shared hosting environment of 1990s and early 2000s. I suppose it has something to do with the use of non-JIT-ted interpreted languages, like PHP, Perl, or SQL, on such hosting; you could not run an arbitrary native executable like you do in the cloud.

Another factor is that though speculative execution was first implemented in 1950s [1], it was either mainframes or RISC machines, and neither was used by the Intel-dominated shared-hosting environments.

[1]: https://en.wikipedia.org/wiki/Branch_predictor#History

dfrageOP6y ago

> It's interesting though why cross-process data exfiltration based on speculative execution was not tried with any success in the shared hosting environment of 1990s and early 2000s.

According to several of the researchers who found Meltdown and/or Spectre, they'd always assumed Intel et. al. were too careful to let this happen, at least at useful data rates. But when they looked for reasons I forget, Katie bar the door!

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