Hello,
10.0.2 was know for issues with whole disk encryption. I suggest to decrypt the drive and encrypt it with atleast 10.3
Restoring a backup of an encrypted drive is not supported as when then backup starts it writes the decrypted data.
Restoring Symantec System Recovery images of machines that have been protected by Symantec Drive Encryption (previously PGP Whole Disk Encryption)
http://www.symantec.com/business/support/index?page=content&id=TECH198084
For more encrypted backup solutions, have a look at the article :
https://www-secure.symantec.com/connect/blogs/encryption-and-disk-imaging-part-ii