What are cryptexes?
Why do they take up so much space on my Mac?

Published: 9th of March, 2023

When using iBoostUp's Disk Usage feature, you may have noticed a large amount of space (around 20GB) allocated to /Volumes/Preboot/Cryptexes on your Mac.

This is totally normal and expected. In simple terms, cryptexes on macOS make sure your copy of the operating system has not been tampered with.

Read on to learn more about cryptexes on your Mac, and why they're so important.

What are cryptexes?

A cryptex on macOS is a cryptographically-sealed archive that contains a well-defined filesystem hierarchy. It is essentially a sealed Disk Image that contains its own file system and is mounted at a randomly chosen location within the root file system during the boot process. macOS verifies the cryptex to ensure it has not been tampered with before mounting it.

Cryptexes on macOS contain various system components, including command tools, system executables, libraries, man pages, apps, frameworks, a "clone" of the OS image and dyld shared caches.

A core feature of macOS security

In conclusion, cryptexes are an important part of macOS to ensure that malware or malicious users cannot tamper with the operating system and it's core tools. Please do not attempt to modify your built in preboot volume or cryptexes folders.

If your Mac is running low on space, there are many other safer ways to free up some disk than tampering with your cryptexes. See Maria's post here for how to do it manually. Alternatively, if you value your time just run a totally free Quick Clean with iBoostUp. Made in Australia by security experts. No catches, no trials, and definitely no spam.