What are the consequences of disabling Kest Signing on OS X Yosemite? I have disabled it to keep TRIM enabled on my aftermarket SSD. What are the security issues I could run up against? If I install applications only from trusted resources can I run in any kind of trouble?

I couldn't find online extensive answers to these questions. Sorry if it's a duplicate.

2 Answers 2


TRIM Support has been enabled for Third Party SSDs in OS X El Capitan. You can google it or watch this Youtube video


It is OK. It is mainly used to detect tampering/modification of device drivers at the kernel level. You should see Trim's note here http://www.cindori.org/trim-enabler-and-yosemite/

In OS X 10.10 (Yosemite), Apple has introduced a new security requirement called kext signing. (A kext is a kernel extension, or a driver, in Mac OS X)

Kext signing basically works by checking if all the drivers in the system are unaltered by a third party, or approved by Apple. If they have been modified, Yosemite will no longer load the driver. This is a means of enforcing security, but also a way for Apple to control what hardware that third party developers can release OS X support for.

  • Disabling kext signing would basically allow any process with root privileges not only to tamper with installed kexts, but also to install new kexts. How do you conclude that this is OK to disable?
    – Synoli
    Nov 22, 2017 at 6:46

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