Backup Software

Only slight related to privacy software, so I apologize in advance.
I'm in the market for a good, yet very simple, software package to use for backing up data to an external drive. Some of the features I really would like are:
1) Preferably open source or free
2) Allows me to select specific folders/subfolders, not have to select every file
3) Backs up to target drive in same structure as on my source drive. i.e. Doesn't lump everything into one master file or folder. Most software packages use some kind of file format specific to their product.
4) Has the option to encrypt data being backed up.
5) Does not require software to do a restore. i.e. can just copy/paste folders from backup location to new hard drive (if old one failed).
6) Provides some kind of differential feature so that it won't do a full backup each time. Ideally, each time I do a backup, it compares the source/target files for changes to the 'date modified' and overwrites the old one with new. If a file is unchanged, then it should skip over it.

Seems like a long list, but those are pretty basic needs (at least I would think so). I have played with a few programs out there, but can't seem to find the one that fits perfectly. Any suggestions?
Thanks!!

 

Cobian Backup can do all of those things, but not all at once! Some of your desired features are mutually exclusive. For example, you can't expect to be able to encrypt your files and then restore them via drag-n-drop without any extra software loaded. Aside from that, Cobian is probably your best bet.

However, if you intend to keep your data in its native format then you should also consider using a synchronization program such as Karen's Replicator or SyncBackSE, although they are not as full-featured as Cobian Backup.

http://www.educ.umu.se/~cobian/cobianbackup.htm
http://www.karenware.com/powertools/ptreplicator.asp
http://www.2brightsparks.com/syncback/syncback-hub.html

edit: typo

 

For just backing up data-use Karens Replicator

 

I'd like to second on Cobian Backup, a very flexable backup program.