macOS Security question

[Keytachi]

I share my Apple with several people in my house, we have an account for each one and, since i take up a lot of space i keep my stuff in the external hard drive (LaCie Porsche F.A. 250GB). But i have some personal files that i want to keep to myself, unfortunatley the internal hard drives cant support them (i could put them in my desktop and problem solved), so i thought of something that would only allow me to open my main folder. The problem is... i dont know much about programming to do that!
So im asking if anyone could help me creating something that would only allow my account (account X) to open my folder (folder Y) or to assign a password to the folder (folder Y).

thanks alot to those who help me

 

[Catfish_Man]

Encrypted disk image.

 

[Keytachi]

the problem is: im not the only one who uses the disk. maybe i could encrypt my folder? is that possible?

 

[Mitthrawnuruodo]

FileVault is for encrypting your whole home folder. But, IMO, that's a bad idea. It's potentially harmful and takes a lot of extra space.

A much better option is to follow Catfish_Man's advice and make an encrypted disk image, or even better an encrypted sparseimage.

What you do is open Disk Utility (it's in /Applications/Utilities/) and select File -> New -> Blank Disk Image..., put it wherever you want (on the internal or external disk) using the Save As..., choose the image's size (ie. how much storage space you need), AES-128 Encryption and sparse disk image under Format. Choose a safe password and wait while it's being made.

You'll then get a sparseimage file that, when double-clicked will prompt for password and then mount itself as a disk. You can copy stuff to and from it, but once you unmount it (cmd-E or drag the disk image - NOT the sparseimage file - to trash), no one will be able to access the data on that without the password (or an immensely strong computer and a lot of time).

Just remember to uncheck the save password on keychain the first time you're prompted for it...

The sparse image will then just take up the space of whatever you put into it (unlike a regular disk image that will take up all the space no matter what's in it).

 

[Keytachi]

wow thanks alot!!! i thought of making an apple script:

tell app finder
encrypt
folder "My folder" in folder "esternal hard drive"
end tell

but then i needed to define the variable "encrypt" but this solution is fantastic!
by the way after copying everything to sparesimage i can erase my folder?

 

[Mitthrawnuruodo]

by the way after copying everything to sparesimage i can erase my folder?

Yes... as long as you don't delete the sparseimage file itself or forget the password...

Also, remember to back up the sparseimage file every now and than. Backup is the best thing you have that you hopefully never will need...

Also, when you drag and drop stuff that you want to move in and out of the encrypted disk, you can hold down the option key (I think it was, or the command key) to get rid of the green (+) that indicates that things are copied over.