Hacker News Reader

It is never a good idea to keep backup copies at the same place as the source data, so normally it should be not that common for an attacker to be able to wipe both original and backup. Regarding the offline optical disc backups, they are still ridiculously expensive compared to magnetic spinning drives or tapes. Backup, especially an automated one, is always an extra security risk to consider, but apparently there are no other good ways...

View on HN

A lot of people put their backups on S3, with a script running on the server. Even if you limit the rights with IAM to only put files, the attacker can overwrite existing files on S3. The only way I thought to prevent that is to give only write access with no listing access, and append a random number to the file name. But, who does that? I'm sure 90%+ of the servers backing up on S3 are not safe for this scenario.

The reason I thought of DVDs is that they're not sensitive to electromagnetic fields as disks and tapes. (You never know: http://www.telegraph.co.uk/science/space/9097587/Solar-flare... )

If you turn on file versioning in S3, then you'll be able to get to the data that was "overwritten". I don't think there's a way for someone with only PUT access to work around this.

Reply on news.ycombinator.com