ARPANET Information Brochure (December 1985)

Clem Cole clemc at
Tue Oct 17 02:09:50 AEST 2017

Don't forget the cost of the IMP itself was just the beginning.  The fees
to 'TPC' for the 1/2 duplex 9600 serial lines in those days were very, very
expensive.   DARPA paid for them for each site in a large deal it had with
AT&T.    I don't remember where I saw it, but what sticks out in my mind
for those days was that cost of a site (host) on the ARPAnet was approx
$125K / year per host in an ARPA grant.

Which really explains 'security.' In practice nobody was going to risk
letting just anyone hack their system so much that it put the site at
risk.   Truth is we did not try to break in because we all had access, but
if it you needed a $.5-2M PDP-10 to connect to the internet, a free IMP
slot (each IMP supplied 4) and the leases on the wires.  So it was just not
practical to think like we do today, much less act that way.

It was not so much security by obscurity, as security by practical
economics.  Moore's law, Ethernet and cheap processing power is what blow
that up.

On Mon, Oct 16, 2017 at 11:38 AM, Don Hopkins <don at> wrote:

> I love the way that geeky guy smugly rubs his hands together, leans back
> and chuckles when he say “We have our very own IMP. (Huh, huh huh, sigh.)”
> I would totally chuckle that way if I had my own IMP.
> -Don
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