[E-Lang] Hash Chaining & Capabilities, Proposal #2d: Deputizing Remote Vats

[Bill Frantz]

At 08:44 AM 11/11/00 -0800, Mark S. Miller wrote:
>Here is the long delayed next step in this proposal for Capability-based 
>Active Invocation Certificates.  For an indefinitely postponed hypothetical 
>piece of engineering, this thread is taking up a distressing amount of 
>paper.  *If* off-line certificates are indeed useful in an increasingly 
>on-line world (a questionable assumption), then I believe this thread will 
>prove important.  Thanks for your indulgence.
>
>(Alan and Bill, you guys are the most qualified to address this 
>questionable assumption, as you've both been heavily involved in engineering 
>efforts with similar goals on both sides of this coin.  (E-Speak 2.2 vs 
>E-Speak 3.0/SPKI; Indra & Pluribus vs SPKI).  Is there a compelling 
>need for off-line certificates?  Do they address a real problem?)

There may be places where a device can listen, but not send.  The classic
example is a missile submarine silently waiting orders to fire.  Similar
situations may occur in other military contexts.

There may be similar non-military situations.  For example, a system which
transmits thru anonymous remailers, and receives thru
alt.anonymous.messages may have slow enough round-trip times to be
practically offline.

Also, radio receive-only devices require a lot less power than
transmit/receive devices.  Power requirements may produce a one-way
communication economic niche.  Wide geographic access may also require a
one-way broadcast solution.  (Think cell phone towers in Antarctica.)

Thinking further out, Moon/Mars/Alpha Centauri/Andromeda communications
give expanding turnaround delays.