old keys in safe storage. Always be aware and make plans for what you're going to do if the worst happens, such as if the data centre burns down. Will you be able to quickly recover your backups? Conclusion Encrypting backups is a very simple thing to do, and should be mandatory if your organisation is sending tapes offsite. If you are using commercial backup tools, like Netbackup, there should also be encryption options which you should investigate and make use of. In this article, I've shown how to configure encrypted backups using OpenSSL and GPG encryption tools - if your backups are driven by plain shell scripts you should have no problems incorporating encryption. I've also shown you how to configure Amanda to use encryption - which is very straightforward in the latest versions of Amanda. Be aware that some other types of backups, for example those which create a bootable recovery system like mksysb on AIX and Ignite on HP/UX may not be able to encrypt their data - so take special care when using these to make backups. On Linux mkcdrec is a very useful backup system which can create a bootable recovery CD and encrypt the filesystem data that is written onto the CD image - it prompts the user for the key when it performs recovery functions.