Care to explain how a hard coded rewrite limit (you stated 720 for NXT) sacrifices decentralization ? What has one todo with the other ?
I'm assuming you're refering to this
New users who encounter multiple histories are no longer able to
distinguish them on their own; they need to ask existing participants in the network (which may
include friends and family, large corporate entities with reputations to maintain, public websites,
etc.) which history they know to be the true one. This is not a distributed consensus! It is a different
sort of consensus, which may be formed amongst always-online peers in a decentralized way, but
10
depends on trust for new users and temporarily offline ones. It is correspondingly vulnurable to
legal pressure, attacks on trusted entities, and network attacks.
?
This makes no sense to me. I'm no expert but if having to trust existing peers is a bad thing then were are new peers supposed to get the chain from if not from existing peers ?
Also I'm not even sure the assumption behind this criticism is accurate. I believe there are ways for nodes to calculate which chain is "better" (in BTC it's simply the longer chain afaik). There are score systems for that in place. I believe both NXT and NEM have something like that so every peer can determine on it's own which "history" is better.
Hi, a nice question indeed!
The real problem is, without a careful design, anyone with very few coins could fake a better chain (a chain has a better score) that switches long ago, with very little effort. In PoW, this is impossible; but in PoS, this is possible. We have some discussion on this topic in section 4.1.2, 4.1.3, and 4.4.4. Hope they help.
If some bad guys control a lot of peers, new peers and temporarily offline peers will not be able to distinguish solely by block chain data. They have to continuously confirm with some "famous" nodes, and those nodes together become the "center" of the network.
The beauty of Bitcoin (or PoW) and LibreFortune is, peers can make sure which is the real main chain solely by block chain data. They do not trust peers, they download data from other peers, validate by themselves, and then make their own decision, whenever they are new peers, or temporarily offline ones.