Back up all files on the flash drive
Choose an encryption method or tool compatible with your operating system
On Windows, use BitLocker To Go if available
On macOS, use Disk Utility to encrypt the drive
On Linux, use LUKS or a compatible encryption tool
Insert the flash drive into your computer
Open the encryption tool
Select the flash drive
Choose the encryption option
Set a strong password or passphrase
Save the recovery key if one is provided
Start the encryption process
Wait for encryption to complete
Safely eject the flash drive
Test unlocking the drive with the password
Store the password and recovery key securely