You mean, the performance impact of the fix published by Microsoft? I know nothing about this fix, but it should not have a big impact on the performance of ProxyCrypt.
Anyway, as it works in user mode, ProxyCrypt is mostly related to Spectre, and implementing Spectre seems rather difficult in practice. About that, you can read the conclusion of the paper.
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Do ProxyCrypt is affect from Meltdown and Spectre bug?
Like most programs, yes. So you have to update your system.
But in my opinion, the "Intel Management Engine" is a much bigger issue. Intel recently admitted a security issue:
https://www.intel.com/content/www/us/en/support/articles/000025619/software.html
But in fact, it goes far beyond:
https://hackaday.com/2017/12/11/what-you-need-to-know-about-the-intel-management-engine/
And of course, AMD has a similar system (TrustZone).
In terms of performance, is it very interested?
You mean, the performance impact of the fix published by Microsoft? I know nothing about this fix, but it should not have a big impact on the performance of ProxyCrypt.
Anyway, as it works in user mode, ProxyCrypt is mostly related to Spectre, and implementing Spectre seems rather difficult in practice. About that, you can read the conclusion of the paper.