Subject: Re: [bitcoin-dev] Three hardfork-related BIPs

From: Natanael <[email-masked]>
Date: Sat, 28 Jan 2017 11:36:16 +0100

Den 28 jan. 2017 05:04 skrev "Luke Dashjr via bitcoin-dev" <
[email-masked]>:

Satoshi envisioned a system where full nodes could publish proofs of invalid
blocks that would be automatically verified by SPV nodes and used to ensure
even they maintained the equivalent of full node security so long as they
were
not isolated. But as a matter of fact, this vision has proven impossible,
and
there is to date no viable theory on how it might be fixed. As a result, the
only way for nodes to have full-node-security is to actually be a true full
node, and therefore the plan of only having full nodes in datacenters is
simply not realistic without transforming Bitcoin into a centralised system.

Beside Zero-knowledge proofs, which is capable of proving much so more than
just validity, there are multi types of fraud proofs that only rely on the
format of the blocks. Such as publishing the block header + the two
colliding transactions included in it (in the case of double spending), or
if the syntax or logic is broken then you just publish that single
transaction.

There aren't all  that many cases where fraud proofs are unreasonably large
for a networked system like in Bitcoin. If Zero-knowledge proofs can be
applied securely, then I can't think of any exceptions at all for when the
proofs would be unmanageable. (Remember that full Zero-knowledge proofs can
be chained together!)