Now that the WWDC keynote is over, Apple has published the names of the developer sessions to attendees at the conference. Previously masked by placeholder names, there are a bunch of events that folks can now plan on attending—including, apparently, a session discussing Apple’s new file system for macOS.

Dubbed APFS, for “Apple File System,” the session description implies that the new file system is a replacement for the aged HFS+ file system, which has been used in one form or another by OS X since its launch back in 2001. We’re pretty light on details at this point, but the session description says that APFS is designed from the ground up to be optimized for use on SSDs and other flash-based media, and that it was “engineered with encryption as a primary feature.”

We don’t know if the new file system is Apple’s own creation or if it’s an adaptation from an existing journaled, encrypted file system. OS X (now macOS) power users have long had hopes that ZFS will take over as Apple’s primary desktop file system—and, indeed, for a while it looked like that’s what was going to happen. With the introduction being made here at WWDC, it’s very likely this is an Apple original.