Compression
Compression, Encryption and Security
How and to what standard is the data
encrypted?
The small files and delta blocks of data are first compressed
and then encrypted with AES, using 128 up to 256 bit key, which
is set by the customer during the installation of the Client Application.
This key is unknown to ebackup and the data remains encrypted
at all times, even when stored offsite (at our vault). The backup
data is only de-crypted by the DS-Client Application at your site
when it has retrieved the encrypted data from ebackup’s
Data centre during a restoration.
What do you mean by compression?
What happens?
Compression can be likened to letting the air out of a balloon.
Although the air has gone, the structure still exists and it
can
be re-inflated easily. The advantage is that it takes less room.
Files, especially databases, are often full of empty space,
which
can be removed to make the file smaller for transit, yet making
it very easy to recreate. We use ZLOP compression.
Is there added compression on already
compressed files (e.g. zip files)?
Zip files and other compressed files are already efficiently
compressed. Rapid Recovery cannot improve on
the compression, but the file will only be transmitted once. If
the file should change, then delta blocking will be used to ensure
that only the changed portions of the file are re-transmitted.
What is delta blocking? How does
it work?
Delta blocking is an advanced logic that divides all files into
4K blocks. When the file is detected to have changed, the Checksum
for the same block is compared to the last known Checksum for
the same block of the same file (stored in the database on the
DS-Client Server). Any blocks that are different are pulled out
to be re-transmitted. These delta blocks will also be compressed
and encrypted before transmission.