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Resources›Change LUKS Password

Change LUKS Password

Tutorial Encryption Security

Change the encryption passphrase on a LUKS-encrypted drive.

This guide assumes you have a drive encrypted with LUKS, such as one created following the Encrypt Drive guide.

Step 1 - Identify the Drive

Plug in and decrypt your encrypted drive. Then identify its device name:

lsblk -o NAME,FSTYPE,FSSIZE,FSAVAIL,MOUNTPOINT

Verify it's the correct drive by checking the LUKS header:

sudo cryptsetup luksDump /dev/sdX

Replace /dev/sdX with your device (e.g., /dev/sda).

Step 2 - Find the Key Slot

LUKS supports multiple key slots. Find which slot your current password uses:

sudo cryptsetup --verbose open --test-passphrase /dev/sdX

Enter your current passphrase when prompted. The output will show the key slot number (usually 0).

Step 3 - Change the Password

Change the passphrase for the identified key slot:

sudo cryptsetup luksChangeKey /dev/sdX -S 0

Replace 0 with your key slot number if different.

You will be prompted for your current passphrase, then asked to enter the new one twice.

Step 4 - Verify the New Password

Test that the new passphrase works:

sudo cryptsetup --verbose open --test-passphrase /dev/sdX

If successful, unmount and eject the drive. Your passphrase has been changed.