Understand that a savecore file (kernel core dump) contains your local secret or secrets. It would be difficult for someone to discern or discover, but it can be done! You should, therefore, protect a core file as carefully as any of your other local secrets.
Remember, if you send your core file out-of-house for analysis, you are giving your local secret to the analyst.
Any system backups made while such a core file exists can contain the core file as well and so must be considered a possible means of discovering your local secret or secrets.
All regular system backups also contain the files in which your local secret or secrets are stored. These backups must be kept in a secure location.