On 01/08/2019 10:56, Gareth's was W7 now W10 Downstairs Computer wrote:
I've been giving some thought as to how to
protect one's privacy from the ever growing
snoopings of the Brit monarchy and all its
lapdogs and subordinate dogs' dinners
such as GCHQ, the MIxs and the po lice,
and to kill off RIPA and the sending of innocent
people to jail for not revealing their
passwords and security keys to the plodderies.

1. In case of computers being seized, you have to
guard against previous data being scattered around
the disk in various deletions. The solution here would
be to store all data in an indexed data base file of
such a size that it won't be moved willy nilly by
the OS. Then, by overwriting records at fixed and
known locations, previous data can be guaranteed
to be deleted.

2. When receiving encyphered messages, the one-time key
is to be the previously received message, giving only
one opportunity to read your message before it takes the
place of the previously received message at the fixed
location in the indexed data base.

3. Still working on data that has to be kept indefinitely,
watch this space.

Not answering the above, but on an associated topic there must be many
people, like myself, who do some consultancy work that is wholy
dependent on computers. There's a small but finite chance that innocent
people might get their systems seized and my understanding is that it
may take months or years to get the hardware and data back. In such a
case, they are instantly out of business *unless* they have all their
data backed up in the cloud, in which case it is just a case of buying a
new laptop and carrying on.

Now, I don't mind having my contacts and calendar together with my
spotify playlist in the cloud. Email is already there. But *some* of my
client data can't go there.

Gareth's stuff above is a bit tinfoil hat to me, but my scenario seems
to me to be a real (if low probability) threat. If you keep an off-site
backup that you don't declare to the police, presumably you are
committing an offence.