can't remember the SSD ScanDisk passphrase

I am using ASUS ZenBook UX31A. I format and reinstall ubuntu instead.
On the left side bar, when i click the SSD Harddisk.
Message below appear.
The passphrase is needed to access encrypted data on ScanDisk SSD i100 24GB

I can’t remember the SSD ScanDisk passphrase when i enter it during purchase of my laptop.

The OS is initially window 8.1. When i do a GParted.

/dev/sda1   fat32     /boot/efi

/dev/sda2   ext2       /boot

/dev/sda3   lvm pv   ubuntu-kylin-vg

I suspect, ASUS is confused, which boot to execute, also window 8.1 boot is still inside. How to verify?