Re: [Din] Minimal assumption for interoperable blockchain systems

Jon Crowcroft <> Sun, 03 June 2018 14:12 UTC

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From: Jon Crowcroft <>
Date: Sun, 3 Jun 2018 15:12:50 +0100
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Subject: Re: [Din] Minimal assumption for interoperable blockchain systems
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looks sane (as did interledger) but we're missing (I think, but may be I
missed it too) one of the big challenges for this compared with scaling
(which is what you have to address in internetworking stuff whether
subnetworks with IP or IGPs with BGP, or serice+content with WWW - that's a
fundamentally difficult piece of distributed ledgers- consistency

one thing the e2e model did for thinking (amongst many) was to think in an
intensely relaxed way about consistency - IP doesn't care if the source is
still where it was when the packet reaches the destination (or even first
hop router. BGP doesn't care (much) about IGP convergance when announcing
(or withdrawing) prefixes and (most) AS paths. WWW doesn't care if the
remote page (server, site or content) are there when you add a URL to your
site - all this is "fixed up later" by some eventual consistency protocol
(in IPs case, TCP;  in the IGP/BGPs case the linkstate and path vector and
a lot of magic pixie dust and luck; in the WWW case, search/rank&shame and
later maintenance) -

so for inter-ledger type thinking, we're connecting systems that
fundamentally care about consistency - but define its eventuality
differently - so a basic building block of an interoperabilty or
inter-domain protocol would be to convey (and somehow reconcile) that
variation in notion of how long before we agree about an append in domain
1, when were' 5 ledger domain hops away...

which reminds me, am I allowed to coin that term "ledgerdomain" ? :-)

On Sun, Jun 3, 2018 at 2:51 PM, Thomas Hardjono <> wrote:

> Here is a question I'd like to throw out to this community regarding
> "interoperable blockchain systems" -- a topic which will undoubtedly come
> to the forefront (assuming it doesn't get drowned-out or killed by the
> barrage of hype about BC):
> -- Minimal assumption: What is the minimal assumption for interoperable
> blockchain systems with regards to the notion of transaction units. In
> other words, what is the “datagram” equivalent of transactions – namely the
> transaction unit that is semantically understandable (processable) by
> multiple different blockchain systems.
> This is a question we posed in our recent discussion paper:
> Would love to get your thoughts on this "datagram" equivalent question (or
> if this framework of thought is even the correct one).
> Best
> -- thomas --
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> Din mailing list