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Main => General Discussion => Topic started by: santaclause102 on July 24, 2014, 08:08:06 pm

Title: POS vs. DPOS
Post by: santaclause102 on July 24, 2014, 08:08:06 pm
Would you agree?

Normal POS:
Contra:
- With competitive tx fees: Gets centralized with those that have a big stake. More centralized than DPOS in the end (if pay back delegates do not flourish).
- [crossed out] If not delegation is not an option, which is assumed here in order to analyze the two different types of systems, a lot of stake (!) has to be online which is pretty insecure. Is that still correct or can you lease (with NXT) to yourself? <- based on this https://nxtforum.org/general-discussion/nxt-pos-vs-bitshares-dpos/msg70367/#msg70367 I would cross out this disadvantage. Further verification would be good though.

DPOS:
Contra:
- Delegates do not have the same interest in the success of the system as when shareholders = forgers.
- An attacker could put up 52 delegates and let them gain the trust of shareholders over a long time and then perform one big attack after which he would be out. This would be cheaper than buying 51 % of the stake but maybe not possible at all.

Further pros and cons?

Higher tx volume and scales better is not an argument because the few forgers with non delegated POS could also have expensive, reliable forging servers and with transparent forging it is known in advance who produces the next block like with DPOS.
Title: Re: POS vs. DPOS
Post by: bytemaster on July 24, 2014, 08:57:19 pm
Regular POS:   Bad Share Holders can still mess with the system *some* of the time.
DPOS:  Bad Shareholders have very little influence over operation of the network assuming the majority are not deceived.

DPOS: Can be attacked by deception of majority, but easily fixed with a quick hard-fork to new delegates.
POS: Can be attacked by deception of majority (leased forging) or by one large actor. 

Assuming large actors are benevolent I guess the systems are equal... but DPOS provides an easier way to reach consensus on change where as large owners effectively control regular POS.   

POS: Controlled by large minority share holders
DPOS: Controlled by majority of shareholders, large minorities have influence but are not sufficient to control.

POS: effectively turns into DPOS in practice, DPOS just streamlines the system
Title: Re: POS vs. DPOS
Post by: santaclause102 on July 24, 2014, 09:33:37 pm
Quote
Regular POS:   Bad Share Holders can still mess with the system *some* of the time.
Why *some* of the time?

Quote
DPOS: Can be attacked by deception of majority, but easily fixed with a quick hard-fork to new delegates.
you mean just replacing the delegates with a hard fork or also hard forking in order to undo the double spend. Both should work right?

Quote
POS: Can be attacked by deception of majority (leased forging) or by one large actor.
I would compare delegation vs. non delegation, abstract, not NXT vs. Bitshares/dpos in order to understand the ad/dis-advantages of delegation better.

Quote
... on change...
What did you mean here?

Quote
POS: Controlled by large minority share holders
Did you mean large majority shareholders?

Quote
POS: effectively turns into DPOS in practice, DPOS just streamlines the system
...if delegation is allowed.
Title: Re: POS vs. DPOS
Post by: bytemaster on July 24, 2014, 09:39:06 pm
Large minority are the only ones who can earn enough to validate profitably under POS.
Large majority would mean they have 51% attack..

*Some* of the time means that if I have .5% of the stake, I can mess with the network .5% of the time. 

Right.. if delegation is allowed.
Title: Re: POS vs. DPOS
Post by: santaclause102 on July 24, 2014, 10:21:04 pm
Understand what you mean.

Let's invite the nxt forum to discuss this: https://nxtforum.org/general-discussion/nxt-pos-vs-bitshares-dpos/
Title: Re: POS vs. DPOS
Post by: Damelon on July 24, 2014, 10:28:07 pm
Decided to register to thank you for crossposting this to our forums :)

Always good to have intercoin discussions!

Title: Re: POS vs. DPOS
Post by: santaclause102 on July 24, 2014, 10:30:30 pm
Always good to have intercoin discussions!
my words ;)
Title: Re: POS vs. DPOS
Post by: santaclause102 on July 24, 2014, 10:44:18 pm
@Bytemaster
here https://bitsharestalk.org/index.php?topic=6102.msg81499#msg81499 you said DPOS is "Faster, Scales Better, Confirms Quicker"
which contradicts
Quote
Higher tx volume and scales better is not an argument because the few forgers with non-delegated POS could also have expensive, reliable forging servers and with transparent forging it is known in advance who produces the next block like with DPOS.
in the OP.
Does one of the systems actually scale better (more tx/sec, more confirmations/minute, more security per "time waited after broadcasting")?
Title: Re: POS vs. DPOS
Post by: lucky331 on July 24, 2014, 11:34:41 pm
Decided to register to thank you for crossposting this to our forums :)

Always good to have intercoin discussions!

hello there.

(http://brandimpact.files.wordpress.com/2011/11/obi-wan_kenobi.jpg)
Title: Re: POS vs. DPOS
Post by: Agent86 on July 24, 2014, 11:41:15 pm
Decided to register to thank you for crossposting this to our forums :)

Always good to have intercoin discussions!
Welcome Damelon!  I just made my first post to the NXT forum (I registered a couple months back), so + 1 for intercoin discussion!
https://nxtforum.org/general-discussion/nxt-pos-vs-bitshares-dpos/msg70361/#msg70361
Title: Re: POS vs. DPOS
Post by: onceuponatime on July 24, 2014, 11:43:14 pm
Decided to register to thank you for crossposting this to our forums :)

Always good to have intercoin discussions!

hello there.

(http://brandimpact.files.wordpress.com/2011/11/obi-wan_kenobi.jpg)

You look quite distinguished!
Title: Re: POS vs. DPOS
Post by: Damelon on July 24, 2014, 11:48:03 pm
Decided to register to thank you for crossposting this to our forums :)

Always good to have intercoin discussions!
Welcome Damelon!  I just made my first post to the NXT forum (I registered a couple months back), so + 1 for intercoin discussion!
https://nxtforum.org/general-discussion/nxt-pos-vs-bitshares-dpos/msg70361/#msg70361

Yes, I saw your first post :)
I am excited by this intercoin discussion.
The Bitshares community also has always seemed very nice and welcoming to me, so I am happy to be here and share and learn.
Title: Re: POS vs. DPOS
Post by: santaclause102 on July 24, 2014, 11:50:59 pm
Based on this https://nxtforum.org/general-discussion/nxt-pos-vs-bitshares-dpos/msg70367/#msg70367 I would cross out this disadvantage:
Quote
Further verification would be good though.  If not delegation is not an option, which is assumed here in order to analyze the two different types of systems, a lot of stake (!) has to be online which is pretty insecure. Is that still correct or can you lease (with NXT) to yourself?
Anyone disagreeing or anyone that can further verify this?
Title: Re: POS vs. DPOS
Post by: Agent86 on July 25, 2014, 12:04:24 am
Ok, I also wrote this complaint about NXT forging on the NXT site:

Aren't forging pools a threat to NXT/centralization?  For instance, I say "lease your forging power to me and I will send back 90% of the fees relative to the stake you leased so you don't need to bother with it."  Even if you limit it by address, I can set up multiple addresses to accept leased forging.  I can also set up pools that don't appear to be under the same ownership but actually are.

The even more sinister attack is I set up a pool that actually returns even more than 100% of fees.  I basically pay people to give me power over the network.  You have to rely on people being altruistic to avert this attack.  People have to reject the short term financial gain for the greater good of the NXT network... That's asking A LOT!
Title: Re: POS vs. DPOS
Post by: Damelon on July 25, 2014, 12:10:46 am
For review, as I have noticed that this often gets overlooked, here is the link to the most current revision of our whitepaper, by the way: https://www.dropbox.com/s/cbuwrorf672c0yy/NxtWhitepaper_v122_rev4.pdf
Title: Re: POS vs. DPOS
Post by: santaclause102 on July 25, 2014, 12:29:19 am
For review, as I have noticed that this often gets overlooked, here is the link to the most current revision of our whitepaper, by the way: https://www.dropbox.com/s/cbuwrorf672c0yy/NxtWhitepaper_v122_rev4.pdf
+1 looks like some quality information!
Title: Re: POS vs. DPOS
Post by: Agent86 on July 25, 2014, 12:50:44 am
Ok, I also wrote this complaint about NXT forging on the NXT site:

Aren't forging pools a threat to NXT/centralization?  For instance, I say "lease your forging power to me and I will send back 90% of the fees relative to the stake you leased so you don't need to bother with it."  Even if you limit it by address, I can set up multiple addresses to accept leased forging.  I can also set up pools that don't appear to be under the same ownership but actually are.

The even more sinister attack is I set up a pool that actually returns even more than 100% of fees.  I basically pay people to give me power over the network.  You have to rely on people being altruistic to avert this attack.  People have to reject the short term financial gain for the greater good of the NXT network... That's asking A LOT!
IMO these are BIG security advantages of DPOS over NXT forging.  APPROVAL VOTING solves these problems in DPOS and creates the right incentives. This allows us the advantages of some centralization for high transaction volume/scalability/efficiency without the security risks of poorly incentivized centralization.