Re: [PLUG] encrypting files with expiration

[brent timothy saner <brent.saner@gmail.com>]

On 02/10/2018 03:24 PM, Rita wrote:
> i would like to archive sensitive tax documents. i would like to store
> the documents so you can't copy and paste -- just view once unlocked.
> set an expiration time once unlocked. are there any tools like that?


this is impossible for a variety of reasons. namely:

0.) data can perform no execution on its own

1.) how would the data know when this expiration happens? how can it
trust the system computer (as the user can change this)? how can it
trust the program that handles this hypothetical data format to actually
delete it (see 0.)? how can it *not be copied* to a saved-state machine?

2.) how does it know it has only been "viewed once"? it would need this
data in a header - which are easily altered. sure, you could
sign/encrypt that header - but then you would need to include the key in
the same file, unencrypted, and we've all seen how well that works out
for... everyone that does that.

etc.

"self-destructing" data is impossible from a technological and
ideological standpoint.

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