alt Hacker News> The most likely attacks on Signal involve trusted insiders or configuration errors, and SGX mostly prevents these, since to exploit it, you'd need to bribe insiders in both Signal and Intel, or find configuration errors in both of their software stacks.
Since there have been multiple SGX key extraction vulnerabilities already, all you would have to do is compromise Signal and then use the key extracted from any of those devices, and "compromise Signal" is the same thing you would have to do if they weren't using SGX at all.
Since there have been multiple 0-day in kernels, we should drop all security boundaries in them because you'd only need execution on the machine and a known vulnerability.
Since there have been with bypass on service X, we should remove auth because all you need is the vulnerability.
Address space layout randomization wouldn't exist with this mindset, and yet it does and helps for many exploits.
SGX is not fully secure. But neither are the other part of the stack. Security (or trust in this case) is done through layers because it's a question of when you'll be vulnerable, not ifs.