Quote from: Daedelus on April 08, 2015, 03:00:04 PM

Quote from: Lorenzo on April 08, 2015, 02:51:32 PM

Didn't Sunny King once say that NXT's PoS algorithm was lifted from Peercoin? I'll see if I can find the quote...

EDIT: Found it:

Quote from: Sunny King

I thought you were the one coded the PoS in NXT. As far as I know at least the first version of NXT's PoS is a direct clone of PPC's with some modifications, appeared lacking a good understanding of the security involved in PPC's PoS. Cunicula instead always wanted a 'hybrid' system involving proof-of-work in security, whereas PPC's security is 100% proof-of-stake.

That said, you are certainly welcome to try some new ideas in the following versions of NXT.

He may have begun with a plan of implementing Peercoin's POS but no Nxt release has ever included it. He thought it was flawed due to being able to accumulate coin age with lots of low stakes. I think this is what led to the dev checkpoints in Peercoin. I'll find his quote...

Not the quote I was looking for but it serves the purpose:

Quote from: BCNext on October 25, 2013, 06:20:37 PM

Block generation is determined by previous blocks. If you are doomed to generate next block in 3 hours you can prepare a block instantly, but you have to wait for 3 hours before you can reveal it (otherwise it will be ignored by the network). You can build millions blockchains in parallel to find the best one for an attack, but at some point you will need someone else to generate a block (or wait again). Nxt uses a novel PoS algorithm, not the one PPC, NVC and other altcoins do. Nxt doesn't have their flaws.

You mean this quote right?

Quote from: BCNext on October 07, 2013, 08:32:49 AM

Quote from: BCNext on October 01, 2013, 10:02:33 PM

Alice has 2500 nxts on her account. Last time she found a block 4 days ago. Her money is like a mining rig with hashpower equal to 2500 * 4 = 10000 GH/s.
Bob has 1000 ntx on his account. He was on vacation and hasn't opened his account for 20 days. His money is like a mining rig with 1000 * 20 = 20000 GH/s hashpower.
Each time Alice or Bob opens their account they have a chance to generate a block. More money they have, higher a chance to do it. More time passed since the previous generated block, higher a chance to generate a new one.
Even a small amount can generate a block by accident.
An exchange that holds coins of its customers can afford to provide the service with 0% fee. It will still earn money via block generation.

After thinking about the mining algorithm I came to conclusion that original proof-of-stake used by PPC and NVC is a bit flawed. Bob could accumulate small amounts on different accounts during a long period of time and then attempt a 51% attack. Artificial limits like max 90 days don't seem to work as intended. Nxt will use a different proof-of-stake approach, I need time to nail some details and then I'll post them here.

I thought by "first version", he meant the first release. Upon further examination, it seems that he chose to move away from PPC's model and use his own implementation of PoS before the first release.