News for hackers. Stuff that matters.
Re:Safety, liveness and fault tolerance—the consensus choices by taspeotis on Saturday December 06, 2014 @06:45AM (#8709015)
I don't know what Stellar is. I had a look at their website. It's a decentralised [1] currency something or other. But this blog post states:

> We were able to replay most of these rolled back transactions on chain B to minimize the impact

And

> To ensure no ledger forks going forward in Stellar, we have decided to temporarily only run one validating node until the new consensus algorithm is live

I don't see the decentralisation here?

[1] https://www.stellar.org/learn/#Decentralized_network "This means that the Stellar network does not depend on any single entity"

Re:Safety, liveness and fault tolerance—the consensus choices by bhouston on Saturday December 06, 2014 @06:53AM (#8709022)
They have de-decentralized so that there are no more ledger splits. Sort of embarrassing but understandable. It is understood that they will re-decentralize once they get a new consensus algorithm I guess.
Re:Safety, liveness and fault tolerance—the consensus choices by makomk on Saturday December 06, 2014 @12:31PM (#8709639)
I don't think they were ever really decentralized except on paper anyway; apparently all five of the nodes making up the Stellar consensus were run by the foundation that created it.
Re:Safety, liveness and fault tolerance—the consensus choices by joyce on Saturday December 06, 2014 @11:42AM (#8709514)
Joyce from Stellar here. Yes, that is correct. When given the choice between temporary centralization and guaranteeing the security of the protocol and therefore user funds, the choice is obvious. Once the new consensus algorithm is complete, it will be safe to run with more than one node again.
Re:Safety, liveness and fault tolerance—the consensus choices by taspeotis on Saturday December 06, 2014 @12:05PM (#8709575)
How'd you centralize your decentralized system? It sounds like something that shouldn't be possible unless it's actually centralized to begin with.

I'm a layperson when it comes to crypto currencies, but my impression is that most people would consider the fact that you can centralize a bug (separate to the hiccup you had in the article).

Re:Safety, liveness and fault tolerance—the consensus choices by polymathist on Saturday December 06, 2014 @01:28PM (#8709797)
I'm just guessing here, and I hope that Joyce or someone from Stellar could correct me if I'm wrong. It could be as simple as announcing that you're going to make this change to de-decentralize, describing what that process entails, and asking all the invested parties (in this case validating nodes) to follow suit. I imagine that the process is similar to when bitcoin has done a hard fork in the past. The bitcoin core developers see the need for a hard fork, announce the hard fork, and ask everyone to update. If the majority of nodes agree than the hard fork was successful. So in Stellar's case, they could be asking people who run validating nodes to update their software, or to simply modify their UNL to point to only a single node (similar to seeding your bitcoin client with only a single peer). I think (and hope) that the Stellar Foundation doesn't have the ability to actually force people to de-decentralize.
Re:Safety, liveness and fault tolerance—the consensus choices by joyce on Saturday December 06, 2014 @03:17PM (#8710036)
Howdy - so at the time of the ledger fork, the Foundation was running all 5 of the validating nodes and there were other parties not associated with us that were running non-validating nodes.

We do not have the ability nor do we want the ability to control other people's nodes.

Since Stellar only launched 4 months ago, the number nodes in the network was still small. In the future, when the network is on the new consensus system and able to run safely in a truly decentralized, then it would be up to individual nodes to decide what to do.

Hope that clarifies things.

Re:Safety, liveness and fault tolerance—the consensus choices by themusicgod1 on Saturday December 06, 2014 @10:55PM (#8711180)
Why wasn't anyone else running a validating node? Where is the code for the validating node?
Re:Safety, liveness and fault tolerance—the consensus choices by nly on Saturday December 06, 2014 @07:28AM (#8709085)
Decentralisation is overrated. Email is decentralised, but there are still powerful actors (Gmail, Outlook, Yahoo, DNSBLs). In Bitcoin they're the miner pools, which, while currently diverse and seemingly quite good at self-regulation[0], have ultimate say over who gets to transact what.

In many ways a centralised, but highly anonymous, digital cash system puts stronger practical limits on the power of a single individual. In such a system the the only way the central authority (bank etc) to doctor history, once money has moved out of their hands, is to drive the entire currency in to the ground and start over.

[0] http://www.coindesk.com/ghash-commits-40-hashrate-cap-bitcoi...

Re:Safety, liveness and fault tolerance—the consensus choices by drcode on Saturday December 06, 2014 @08:23AM (#8709172)
Decentralization is not overrated, just misunderstood. The primary concern should be whether a central entity can change the agreed-upon communication protocol at will (i.e. arbitrarily change the "rules" of the money)

With Bitcoin, such a change is very difficult. With stellar, it is easy for the central Corp to change the rules at it's whim.

Re:Safety, liveness and fault tolerance—the consensus choices by joosters on Saturday December 06, 2014 @09:16AM (#8709238)
What?

Without decentralisation, Bitcoin has nothing to offer over everyone trusting some random entity offering to keep a ledger of account balances. And we already have plenty of those around.