I am u/314stache_nathy (I posted this), PoS have problems and make a hybrid sistem with PoW+PoS is bad why PoS have  'long-range attacks' and 'nothing-at-stake'.

PoW is better than PoS and a hybrid sistem have other problems (in adition with PoS problems), like:

• Complexity
• The big players only be more big with time, the rich will be more rich
• The PoS turns all blockchain vulnerable to mentioned attacks (long-range attacks and nothing-at-stake).

IMO, while a hybrid approach might be eventually necessary, I don't see PoS as part of the solution. But there are viable solutions (see below).

The problem with Qubic is that a few players can (temporarily) disrupt the network. The tokenomics of Qubic allow it to attack temporarily but it will ultimately fail by that same tokenomics. With PoS, the problem is that a few players (the stakers) can disrupt the network. The requirements for staking (e.g. not turning off your machine for a set period of time, etc) encourage people to stake with a service so it encourages non-custody and centralization. And since PoS gives stakers more stake, their power to disrupt can only grow.

So you're trying to fix one set of disruptors by adding a second set of disruptors. Not exactly a solution, IMO.

Of course there's slashing. If it's purely algorithmic slashing, then it can be gamed and taken advantage of by either disruptor. If it's "trusted individuals" then you're just adding another set of disruptors to the mix. With so much complexity and potential for collusion, it's almost certain that failure will eventually result.

So what's possible? There are other consensus mechanisms that greatly reduce block reorderings like GhostDag (see Kaspa) that might be used to support the current PoW. Nano also has no transaction fees and seems to keep working. Instant validation of mutually agreed upon transactions also work if both parties are online at the same time (it doesn't work otherwise). If I give you cash, and you accept the cash and give me a receipt for that cash in real life, I don't need a third party to validate it so it would be wrong for a third party to not confirm it on the blockchain as finalized. You can even add the condition of having both parties have a copy of the receipt and both parties have to sign it. That extra condition is usually a part of the transaction of big ticket items like houses for extra security. True this approach wouldn't work if one party is offline, but since I estimate for over 90% of transactions both parties are online (since NFC cards aren't common but phones and computers are), this approach would all the blockchain to keep working even if there is an attack. The other supports are there for offline transactions.

I think the majority of the Monero community shares this concern. If there was a better solution for the purposes of securing a decentralized ledger, we'd move on it quickly. Problem is, in all these years, as a community we haven't seen a better system.

PoS tends to continually centralize power. End of story. There is no situation where PoS does not ultimately fully centralize.

Ostensibly super fast mechanisms like Nano are subject to insane re-orgs, which they mitigate by checkpointing the chain, which means the re-orgs that should have happened, don't happen, ... it's a frickin' trainwreck and would be exposed as such under real-world high scale loads.

IMO the next-best solution to PoW is Federated Byzantine Agreement (FBA) aka "validator nodes" like Stellar. These are crazy high throughput, super efficient, and slightly more centralized -- that wallets have to choose a set of validator nodes, and hope that those nodes are not colluding.

Think of FBA Federation as being like the Fediverse: there are semi-centralized hubs. But anyone can spin up a hub and people can migrate easily. It's not 100% decentralized where every node is identical. But you get orders of magnitude more throughput and less electricity use.

@Electricd @LogicallyMinded this is debatable. I do not use much my computer, therefore, I better set it on mining rather than collecting dust.

In the winter time I set it towards max so it also produces heat and it lowers my heating bill also diminishing gas burns and reducing pollution.

In the summer time, I have to set it on very low, as the heat produced is really unbearable. Again, I would save on electricity bill as computers today are very power efficient, thus reduce pollution too.

This argument often comes up to claim that PoS would be less secure than PoW but let's examine it closer.

Hashpower can also be bought and if you think about it would be cheaper to buy 51% of the hashpower than 51% of the XMR supply. CPU price would not increased as much as XMR price as the attacker attempt to buy enough resources to reach 51%. Plus, it's easier for Monero holders to mount a counter attack as staking takes two clicks of a button while running a miner is more cumbersome.

Running an effective 51% attack like the one ran by Qubic is a lot cheaper than attacking PoS. The attacker needs is to create a bogus blockchain with manipulated supply and market it well to incentivize the miners well enough. The attacker doesn't risk his own capital in the attack (since he's a seller of XMR not a buyer).

Again, Qubic isn't even a state sponsor attack. It's conducted by a new and small project and it has been successful at creating enough panic to see the price of XMR dropped significantly. With this in mind, how can you justify that PoW on Monero would be more secure than PoW/PoS considering that the XMR supply has been, as you said, fairly distributed from the start.

It's been repeated so much that Monero will never adopt PoS that to many it's inconceivable that PoS becomes one day part of the security mix but this Qubic's attack will certainly force us to reconsider this stance.