[Info-vax] Current state of file/disk encryption on VMS

[Alexander Schreiber]

David Jones <osuvman50 at gmail.com> wrote:
> On Thursday, September 1, 2022 at 5:08:04 PM UTC-4, Alexander Schreiber wrote:
>> Well, that is actually the right thing do to from a crypto security 
>> point of view. Compressed files tend to have specified headers and 
>> structures, which means that "compress, then encrypt" potentially 
>> enables a nice automatic known plaintext attack. And I suspect that 
>> is the reason it was done this way.
>
> I'm guessing the redundancy blocks backup includes by default weaken the
> encryption also.

Not really, unless their content can be reliably predicted without
decryption (which I assume is not true).

Kind regards,
           Alex.
-- 
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 looks like work."                                      -- Thomas A. Edison