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  • Re: Encryption program - recommendation?

    From Bruce@07.013@scorecrow.com to uk.comp.sys.mac on Sat Feb 28 23:50:36 2026
    From Newsgroup: uk.comp.sys.mac

    On 27/02/2026 08:55, Martin S Taylor wrote:
    On 26 Feb 2026, Bruce wrote
    (in article<485acdd0-6220-4a80-a8ab-4e6dc36dcaa0@scorecrow.com>):

    On 26/02/2026 16:42, Martin S Taylor wrote:
    Hi:

    IrCOm looking for an encryption program with the following (rather specific) requirements. Can anyone help?

    1. Encrypts at the file level, so that although I have a folder containing several GB of stuff, I donrCOt need to backup the whole shebang every time I modify one tiny file.

    2. I can modify a file without making an unencrypted copy on my computer, which I then have to securely delete when IrCOve finished with it.

    3. Opensource

    4. Inexpensive

    5. A standalone program, which I can delete from my hard drive if necessary.

    6. Not Cryptomator (which does all the above, but which I canrCOt use, for complicated reasons).

    Thanks in advance.

    Martin S Taylor

    You could use encrypted disk images, one per file.

    To make life a little easier, Automator has a "New disk image" action
    with an "encrypt" tick box, an option to make the image just big enough
    to hold the original and an option to create the image file in the same
    directory as the original. So that makes it amenable to building into a
    script/droplet where you drag and drop the target file onto it and out
    pops a .dmg

    Yes, but an awful faff, considering there are hundreds of files I need to encrypt, and IrCOd have to decrypt them individually to look at them. Also this fails my requirement number 5.

    I thought that you *wanted* to be able to encrypt/decrypt files
    individually, potentially using a different password for each.

    If you don't - i.e. you're happy to use one password for multiple files
    - then just use an encrypted sparsebundle.

    You create the sparesebundle, set the encryption option, and then copy
    files into it like any mountable image. Once copied-in the files are encrypted. If copied-out then they are decrypted. The act of mounting
    the image doesn't actually cause a mass decryption to happen: decryption
    is on demand as the data is accessed, and happens invisibly as far as
    you are concerned.

    To your backup software, an unmounted sparsebundle just looks like a
    folder containing lots of small files and only those that change need be backed up, so your backup is efficient.

    You can even use an S/MIME public certificate to encrypt a sparsebundle instead of a local password. In fact you can use more than one so, for example, you and a business partner could both work on the same
    encrypted sparsebundle shared via iCloud or DropBox without having to
    share the password with each other.

    Regards,
    --
    Bruce Horrocks
    Hampshire, England
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