@anunymint
As of classical selfish attack itself, I personally disagree to call it an attack at all. I rather see it as a fallacy, a straw man fallacy.
My reasoning:
PoW has nothing to do with announcement. Once a miner prefers to keep his block secret it is his choice and his right as well, he is risking his block to become orphan in exchange for a possible advantage against the rest of the network in mining for the next block.
Although Like PoW, this proposal is not about prohibiting people from selfish mining, there is a point to rephrase the above reasoning somehow different, this proposal is about reducing the pooling pressure and helping the network to become more decentralized by increasing the number of miners. How? By reducing the variance of mining rewards that is one of the 2 important factors for this pressure (I will come back to the second factor, soon).
So, it might be a reasonable expectation from PoCW to have something to do with selfish mining.
It has, but first of all it is worth mentioning, according to the protocol, miners are free to choose not to collaborate and go solo if they wish although by keeping the costs of participation very low and the benefits high enough, this practice is discouraged.
PoCW improves this situation by reducing the likelihood of pools to take place, eliminating one of the most important factors that makes their existence possible at all.
Your second objection but happens to be about the second important factor for pooling pressure: proximity.
It is about taking advantage of having access to information (a freshly mined block for instance) and taking advantage of it or not having access to such an information and wasting resources (mining stall blocks) because of it. Even with completely loyal nodes in bitcoin and other PoW based networks, there is always a proximity premium for the nodes nearer to the source (lucky finder of the fresh block) compared to other nodes.
I have to accept that by pushing for more information being circulating around, PoCW, this proposal, is suspected to enforcing this second pressure for pooling.
I have been investigating it for a while and my analysis suggests otherwise. It is a bit complicated and deserves to be considered more cautiously I need to remind that proximity premium is known flaw for PoW's decentralization agenda.
For a traditional winner-takes-all PoW network, like bitcoin there is just one pieces of information (the fresh block) that causes the problem, true, but the weight of this information and resulting premium is very high and it is focused in one spot, the lucky miner in the focal point and its neighbors in the hot zone.
For this proposal, this premium is distributed more evenly, tens of thousands times.
OOps! there is almost no proximity premium flaw in Proof of Contributive Work!
Without a proximity premium and a mining variance flaw, there will be no mining pressure, no threat to centralization. It is how selfish mining concerns (again not a flaw) are addressed too. It turns to become a simple, innocent solo mining.
As of @tromp's and your concerns about share validation overhead, I have already addressed it, there is no resource other than a few cpu cycles to be consumed for it, not a big deal according to my analysis and by distributing the proximity premium almost evenly, it does more than enough to compensate
As of classical selfish attack itself, I personally disagree to call it an attack at all. I rather see it as a fallacy, a straw man fallacy.
My reasoning:
PoW has nothing to do with announcement. Once a miner prefers to keep his block secret it is his choice and his right as well, he is risking his block to become orphan in exchange for a possible advantage against the rest of the network in mining for the next block.
Although Like PoW, this proposal is not about prohibiting people from selfish mining, there is a point to rephrase the above reasoning somehow different, this proposal is about reducing the pooling pressure and helping the network to become more decentralized by increasing the number of miners. How? By reducing the variance of mining rewards that is one of the 2 important factors for this pressure (I will come back to the second factor, soon).
So, it might be a reasonable expectation from PoCW to have something to do with selfish mining.
It has, but first of all it is worth mentioning, according to the protocol, miners are free to choose not to collaborate and go solo if they wish although by keeping the costs of participation very low and the benefits high enough, this practice is discouraged.
PoCW improves this situation by reducing the likelihood of pools to take place, eliminating one of the most important factors that makes their existence possible at all.
Your second objection but happens to be about the second important factor for pooling pressure: proximity.
It is about taking advantage of having access to information (a freshly mined block for instance) and taking advantage of it or not having access to such an information and wasting resources (mining stall blocks) because of it. Even with completely loyal nodes in bitcoin and other PoW based networks, there is always a proximity premium for the nodes nearer to the source (lucky finder of the fresh block) compared to other nodes.
I have to accept that by pushing for more information being circulating around, PoCW, this proposal, is suspected to enforcing this second pressure for pooling.
I have been investigating it for a while and my analysis suggests otherwise. It is a bit complicated and deserves to be considered more cautiously I need to remind that proximity premium is known flaw for PoW's decentralization agenda.
For a traditional winner-takes-all PoW network, like bitcoin there is just one pieces of information (the fresh block) that causes the problem, true, but the weight of this information and resulting premium is very high and it is focused in one spot, the lucky miner in the focal point and its neighbors in the hot zone.
For this proposal, this premium is distributed more evenly, tens of thousands times.
OOps! there is almost no proximity premium flaw in Proof of Contributive Work!
Without a proximity premium and a mining variance flaw, there will be no mining pressure, no threat to centralization. It is how selfish mining concerns (again not a flaw) are addressed too. It turns to become a simple, innocent solo mining.
As of @tromp's and your concerns about share validation overhead, I have already addressed it, there is no resource other than a few cpu cycles to be consumed for it, not a big deal according to my analysis and by distributing the proximity premium almost evenly, it does more than enough to compensate