Re: secure backups

[Fred Cohen <fred.cohen () all net>]

No. - Sort of.

Understanding the rationality and effectiveness of an approach is not  
as simple as it may be portrayed. Passwords are effective at  
mitigating specific threats for specific time periods under specific  
conditions. And the mechanism by which the password is applied is  
also important to understand. Here are two examples that help to  
bring some of these issues to light:

Suppose the password is on the hard drive controller and the drive  
itself is encrypted internally so that without the password the  
content does not properly decode. Then the password may be adequate  
unless the attacker has a strong capability to plant a Trojan in the  
disk or try many passwords or decrypt the content directly by  
removing the controller and replacing it with one that allows more  
direct access followed by decryption.

Suppose the password is the first file on the tape drive and the  
software reads it to determine if it can then read the rest of the  
tape. Trivially bypassed by moving the tape up a file and reading.  
Trivially forged by replacing the password file with another to which  
you know the password.

You need to provide a complete description in order to have a  
properly knowledgeable expert analyze a situation relative to the  
these issues. These problems are far more complex than your question  
belies.

On Oct 30, 2005, at 2:00 PM, Kirk Brady wrote:

> Hi Steven
>
> Is password protecting the media/session not enough? Do members of  
> the super users group need to be able to add/modify the jobs, or  
> just be able to run them? Most backup software can work with any  
> user that has Read permissions for the backup target, and can  
> incorporate password level protection for the session or media  
> which is needed for a restore. Unsure how this holds up to a brute  
> force attack though.
>
> HTH
> Kirk Brady
>
> -----Original Message-----
> From: Steven Meyer [mailto:meysteven () gmail com]
> Sent: Saturday, 29 October 2005 12:52 AM
> To: security-basics () securityfocus com
> Subject: secure backups
>
>
> I am looking for a backup software that only the Superusers could use
> to backup, but only the administrator could restore. That way nobody
> could bring data out from the office and I wouldn't need to do
> regularly backup on the user computer.
> May be the backup should be done with a private and public key.
> If anybody has a good idea, it would be very appreciated.
> thank you
> Steven Meyer

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