Encrypting backups for additional security
Backup tapes present a special security problem because good practice requires multiple copies with at least one copy stored securely off site. One way to enhance security is to encrypt the data as it is being backed up. The information can still be read with the appropriate software and encryption keys, but it is much harder for an unauthorized person to decipher.
A number of software packages automatically encrypt files before storing them or backing them up and several backup programs will perform encryption either when writing to disk or when backing up to tape. For example NetBackup Datacenter and NetBackup Business Server from Veritas Software Corp. (
Another level of security is represented by hardware that encrypts data between creation and storage. One example is the appropriately named "Paranoia" tape encryption system from Digital Interactive Solutions (www.digital-interact.co.uk). This is a unit with two fast wide differential SCSI ports that sits between the host system and a tape drive. It uses both a hardware key unique to each unit and a software key to encrypt data at a sustained rate of 15 megabytes per second using the DES standard with a 56-bit key.
Of course encryption is only as strong as the protection afforded the keys. If you use encrypted tapes for backup you need to establish and enforce appropriate procedures for safeguarding access to the keys.
Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
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An Information Security Handbook
Author : John M.D. Hunter
Publisher : Springer-Verlag
Published : May 2001
Aimed primarily at final year undergraduate courses and MSc courses on Information Systems, Management of Information Systems and Design of Information Systems, this textbook aims to provide answers to five questions; What is security? What are the security problems particular to an IT system? What can be done to reduce the security risks associated with such a system? In a given situation, what are the appropriate security countermeasures? How should one set about procuring an information system with security implications? It looks at the different goals organisations might have in employing security techniques (availability, integrity, confidentiality, exclusivity) and which technique is best suited to achieving each goal. With guidelines appropriate for the protection of both conventional commercial and military systems, An Information Security Handbook will be of interest to computer system managers and administrators in any commercial or government organisation.
This was first published in July 2001