Global network consensus means that there is global network recognition that a particular transaction has occurred and is irreversible. The off-chain solutions you describe, while probably useful for other purposes, do not exhibit this characteristic and so they are not global network consensus networks. 

Bitcoin Core scales as O(N), where N is the number of transactions. Can we do better than this while still achieving global consensus? 


On Sat, Jun 27, 2015 at 12:37 PM, Peter Todd <pete@petertodd.org> wrote:
On Sat, Jun 27, 2015 at 12:09:16PM -0400, Michael Naber wrote:
> The goal of Bitcoin Core is to meet the demand for global consensus as
> effectively as possible. Please let's keep the conversation on how to best
> meet that goal.

Keep in mind that Andresen and Hearn both propose that the majority of
Bitcoin users, even businesses, abandon the global consensus technology
aspect of Bitcoin - running full nodes - and instead adopt trust
technology instead - running SPV nodes.

We're very much focused on meeting the demand for global consensus
technology, but unfortunately global consensus is also has inherently
O(n^2) scaling with current approaches available. Thus we have a fixed
capacity system where access is mediated by supply and demand
transaction fees.

> The off-chain solutions you enumerate are are useful solutions in their
> respective domains, but none of them solves the global consensus problem
> with any greater efficiency than Bitcoin does.

Solutions like (hub-and-spoke) payment channels, Lightning, etc. allow
users of the global consensus technology in Bitcoin to use that
technology in much more effcient ways, leveraging a relatively small
amount of global consensus to do large numbers of transactions
trustlessly.

--
'peter'[:-1]@petertodd.org
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