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From: Paul Winalski <paul.winalski@gmail.com>
Date: Thu, 8 Sep 2022 12:47:56 -0400
Message-ID: <CABH=_VSDKNiwYJ1_fNWuxdcV1DPBNj07tke+PhSqO14AC61GBg@mail.gmail.com>
To: Warner Losh <imp@bsdimp.com>
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Subject: [TUHS] Re: Has this been discussed on-list? How Unix changed Software.
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On 9/8/22, Warner Losh <imp@bsdimp.com> wrote:
>
> In addition, when Dennis would talk about Coherent and his evaluation of
> the source code, he said he used the known to him, but not widely known
> bugs in Unix to try to catch copying. If there was copying, those would be
> copied. If it was freshly implemented, there's a high likelihood that they
> wouldn't. His conclusion was that someone had access to a lot of knowledge
> about the Unix system given the fidelity of the implementation, but the
> lack of bugs and novel ways of doing it suggested independent
> implementation.

The software equivalent of a common technique used by mapmakers to
detect copying.  You sprinkle a few fake locations or other deliberate
errors into your map.  If these show up in a competitor's map you know
they were copied.

-Paul W.