[tahoe-dev] deleting encryption key vs. deleting ciphertext (was: Noob questions)

George Goodman georgegoodman at gmail.com
Sat Aug 23 03:22:48 UTC 2008


Hi Zooko,

Thanks for the help.

> If you can tell us a bit about the project that you are developing,
> I would be interested to hear about it.

Unfortunately it's under wraps at the moment, but I will eventually be
able to tell :)

> You are correct that a user who initially uplodas/creates a mutable
> file or a directory automatically gets the read-write cap to that
> directory.

Ok, thanks

> The confusion lies in the fact that the section of
> architecture.txt that you were reading is talking about deleting
> ciphertext to free up disk space for re-use, while deleting a read-cap
> means deleting the encryption key, thus making the ciphertext
> indecipherable.

Ok, so to be clear, I understand that if I have read-write cap I can
delete the cap making the data inaccessible, but currently there is no
way of freeing up disk space, all data remains on the servers
indefinitely.

What of an immutable fie/directory? I assume that for such an object
the cap is read-only. Can I delete that cap?

If I wish to manage the volume of data on the server(s), I assume I
can use mutable files, and simply replace  "large" data files with
tiny ones. So for example if I have a mutable 1GB file, and I have
read-write cap, can I  replace it with a 1KB file and consequently
recover the space on the server?


Regards,

GG



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