<story><title>Ethereum Proof of Stake FAQ</title><url>https://github.com/ethereum/wiki/wiki/Proof-of-Stake-FAQ</url></story><parent_chain><item><author>xorcist</author><text>Ethereum was supposed to have every feature under the sun from the start, proof-of-stake perhaps being the second most hyped. (Turing completeness being the clear first, which is problematic given the halting theorem and all that, so it&amp;#x27;s now rich statefullness instead.) And PoS is one of those ideas that most people looking at cryptocurrencies end up trying some variant of. PoW is obviously wasteful and it would be nice to improve on that. The problem is that it doesn&amp;#x27;t have the same properties as PoW have, and that are hard to do without.&lt;p&gt;The problems are the basic ones, how to avoid colluding stakers, how to neuter the market for consumed stakes, how to deter chain splits. There is a constant flow of new coins that try various approaches, but the ones that have survived have all had to resort to some variant of checkpoints where a trusted third party decides on regular intervals which chain is valid. This has obvious implications for a supposedly trustless digital currency, where you don&amp;#x27;t really need that complicated blockchain anymore.&lt;p&gt;This Ethereum PoS FAQ is much like other documentation from the Ethereum Foundation quite dense where most paragraphs introduce terms not seen elsewhere (economic finality? slashing? weak subjectivity?). If you want the interesting bit, the TL;DR, then skip to the part about weak subjectivity. Read it, and then read it again and bear in mind how other coins solved this problem.&lt;p&gt;Tell me I&amp;#x27;m wrong, but I think this bit with the key part being that the node &amp;quot;authenticate out of band&amp;quot;, involve a certain third party with a Very Important Key. In which case the rest of the theory in the document doesn&amp;#x27;t matter much, does it?</text></item></parent_chain><comment><author>paulmd</author><text>I&amp;#x27;m in total agreement about the dangers here.  It seems absolutely insane to institute these kind of untested changes on a production system.  These belong in some other coin, not Ethereum.&lt;p&gt;Furthermore it&amp;#x27;s insane that miners are just going along with this plan.  They think since they hold Ethereum now that they will receive greater future rewards - but this is literally a parable that we warn our children about - &amp;quot;The Goose That Laid The Golden Eggs&amp;quot;.&lt;p&gt;&lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;www.mythfolklore.net&amp;#x2F;aesopica&amp;#x2F;perry&amp;#x2F;87.htm&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.mythfolklore.net&amp;#x2F;aesopica&amp;#x2F;perry&amp;#x2F;87.htm&lt;/a&gt;&lt;p&gt;If these changes were simply switched on then they would have absolutely no chance of standing, there would be an immense backlash.  VB is exploiting social-engineering to push these changes with the whole &amp;quot;Ice Age&amp;quot; scheme.  Gotta boil that frog slowly.</text></comment>
<story><title>Ethereum Proof of Stake FAQ</title><url>https://github.com/ethereum/wiki/wiki/Proof-of-Stake-FAQ</url></story><parent_chain><item><author>xorcist</author><text>Ethereum was supposed to have every feature under the sun from the start, proof-of-stake perhaps being the second most hyped. (Turing completeness being the clear first, which is problematic given the halting theorem and all that, so it&amp;#x27;s now rich statefullness instead.) And PoS is one of those ideas that most people looking at cryptocurrencies end up trying some variant of. PoW is obviously wasteful and it would be nice to improve on that. The problem is that it doesn&amp;#x27;t have the same properties as PoW have, and that are hard to do without.&lt;p&gt;The problems are the basic ones, how to avoid colluding stakers, how to neuter the market for consumed stakes, how to deter chain splits. There is a constant flow of new coins that try various approaches, but the ones that have survived have all had to resort to some variant of checkpoints where a trusted third party decides on regular intervals which chain is valid. This has obvious implications for a supposedly trustless digital currency, where you don&amp;#x27;t really need that complicated blockchain anymore.&lt;p&gt;This Ethereum PoS FAQ is much like other documentation from the Ethereum Foundation quite dense where most paragraphs introduce terms not seen elsewhere (economic finality? slashing? weak subjectivity?). If you want the interesting bit, the TL;DR, then skip to the part about weak subjectivity. Read it, and then read it again and bear in mind how other coins solved this problem.&lt;p&gt;Tell me I&amp;#x27;m wrong, but I think this bit with the key part being that the node &amp;quot;authenticate out of band&amp;quot;, involve a certain third party with a Very Important Key. In which case the rest of the theory in the document doesn&amp;#x27;t matter much, does it?</text></item></parent_chain><comment><author>Pyxl101</author><text>I don&amp;#x27;t know much about the Etherium,  but I don&amp;#x27;t see what problem there is with respect to Turing completeness and the halting problem.&lt;p&gt;My understanding was that programs are limited to a finite number of steps in the Etherium virtual machine.</text></comment>