IT Baseline Protection Manual - The Information Warfare Site

Safeguard Catalogue - Communications Remarks
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S 6.71 Data backup for a mobile IT system
Initiation responsibility: IT Security Management Team, Head of IT
Section
Implementation responsibility: Administrator, IT users
Mobile IT systems (laptops, notebooks) are generally not permanently
integrated into a network. Data exchange with other IT systems is normally
effected over data media or temporary network connections and can, for
example, be implemented through remote access or direct connection to a
LAN on returning to the workplace. Unlike with stationary clients, it is
therefore generally unavoidable with mobile IT systems that data at least
temporarily has to be stored locally instead of on a central server. Appropriate
data backup measures must be taken to prevent loss of this data.
Generally the following data backup procedures are available:
1. Data backup on external data media
The advantage of this method is that the data can be backed up in virtually
any location and at any time. The disadvantage is that a suitable drive and
sufficient data media must be carried and that proper handling of the data
media entails additional effort on the part of the user. The data media
should possess sufficient storage capacity so that the user does not have to
insert several media into the drive every time a backup is performed.
Where the data is kept in unencrypted form, there is also the danger that
data media could get lost and that as a result sensitive data could be
compromised. The data media and the mobile IT system should as far as
possible be kept separate from each other so that in the event of loss or
theft of the IT system the data media are not lost as well.
Storage on external data media for data backup purposes is especially
recommended where data is also exchanged with other IT systems using
external data media, as it may be possible to combine the two processes.
On returning to the workplace, the data backups on the data media must be
incorporated into the backup system or the operational system or into the
central databank of the organisation.
2. Data backup over temporary network connections
If it is possible to connect the IT system to a network regularly, for
example using remote access, the local data can also be backed up over the
network connection. The advantage of this is that the user does not have to
bother with any data media, nor does he have to take the appropriate drive
along with him. Moreover, the procedure can be largely automated, for
example, with remote access data backup can be automatically initiated
following every dial-in.
When backing up data over a temporary network connection it is essential
that the bandwidth of the connection is adequate for the volume of data to
be backed up. Transmission of the data must not take too long or lead to
excessive delays if the user has to access remote resources at the same
time. With current access technologies (e.g. ISDN, modem, mobile phone)
this means that only low volumes of data can be transported on each
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IT-Baseline Protection Manual: Oktober 2000