HP Data Protector Express Basic-Software - Manual (Page 42)

block of data to be encrypted, which may slow down the data stream to the device and will increase
CPU loading on the Media Server.
Encryption passphrase / Verify Passphrase
The user-supplied portion of the encryption key. Data Protector Express will use this value, along
with other information it generates, to calculate an encryption key for the media. The passphrase
must be entered twice to minimize the change of making a mistake while typing.
Hint
The text entered here will be added to the log file of an import job if the media later needs to be
imported and the incorrect passphrase is supplied. Use this field to create a reminder of the
passphrase because Data Protector Express cannot recover a lost passphrase.
Key Management
Data Protector Express has adopted a very simple key management strategy. A media is encrypted
originally by configuring the job that creates it according to the parameters described above. From
that point on, the media is known to the catalog. As long as the media is known, restore jobs may
use the media without entering the passphrase again. If a media is unknown — because it was
deleted from the catalog or because it came from a different catalog — you must import the media
to make it known to the catalog again. The import process required you to supply the passphrase
to complete the import. If the passphrase supplied does not match that used to encrypt the media,
then the hint supplied at encryption time will be shown in the job log so you can try the import
again.
When media is encrypted the media is depicted on the Jobs and Media view with a lock on it.
The Platinum colored lock indicates hardware, whereas the gold lock indicates software encryption.
The Media details window shows the type of encryption used.
Compression
Software encryption disables hardware compression, although you will still be able to select
Software compression.
If the backup device has hardware compression then performance will be better if only hardware
compression is used, and that there is little to no benefit of having both enabled. Enabling software
compression in this circumstance will reduce performance.
If Hardware encryption is selected, HP recommends that Enable hardware compression is also
selected. Hardware encryption and hardware compression can be used on devices, such as the
HP LTO-4 tape drive, without loss of backup speed.
42 Encryption and Compression