Using two-factor authentication increases the security of data on your system. Two-factor authentication uses "something you know" (your passphrase) and "something you have" (your USB flash device) to verify that you are who you say you are and are entitled to access the disk. 
 

To protect a disk using PGP Whole Disk Encryption with two-factor authentication

 

1. Open PGP Desktop and click on the PGP Disk Control box.
2. Click Encrypt Whole Disk.
3. In the Encrypt Whole Disk (Partition) work area, in the Select disk or partition to encrypt section at the top, click to select the disk or partition on your computer that you want to protect using PGP Whole Disk Encryption.
4. Choose the Encryption Options that you want to use, if any.
5. In the User Access section, select New Passphrase User.
6. Select Create New Passphrase, then click Next.
7. In the PGP Disk Assistant: Two Factor Authentication dialog box, select Generic USB Flash Device and select the device from the list.
8. Click Next.
9. Type the name of the new user and the passphrase you want associated with the user.
10. Type the passphrase again in the Confirm field and click Next.
11. Click Finish.

After creating a new passphrase user, click the Encrypt button to begin PGP Whole Disk Encryption of the disk.