The incentives for running full nodes seems like a potential problem in the long run. The incentives for running P-nodes and V-nodes are clear and tied to staking and fees, but the incentives for running and maintaining full nodes which have the complete record of the distributed ledger (of all shards for all time) are not as strong or clear (i.e. the value of “decentralization” is some incentive but probably not enough).
This seems like it would lead to the appearance of decentralization on the one hand because p-nodes and v-nodes (which only keep records of the shards they are in, if I understand correctly) and the reality of centralization of (or far fewer) full nodes which contain the REAL complete distributed ledger record of the entire incognito blockchain. Developers of pApps and businesses would be incentivized to maintain full nodes, but not individuals who are incentivized by the proof of stake p-nodes and v-nodes. It is like maintaining one part of the infrastructure of Incognito Network has much more incentive than another (full nodes) which are equally, if not more, important for the security of the whole network.
Some technical questions come to mind: Is there an appropriate ratio of full nodes to (p-nodes and v-nodes) that must be present for the security of the network to be assured? Would a small number of full nodes cause any additional security threats to the network? While (if I understand correctly, which I might not) p-nodes and v-nodes are producing blocks, those blocks as parts of (or occurring in) shards must still be “stitched” securely together somehow presumably by consensus mechanisms in the full nodes (the “glue” that holds all the shards together I assume). What types of risk does a small number of full nodes pose should there be a number of malicious full nodes (even with no malicious p-nodes and v-nodes)? It was mentioned in the description of “dynamic sharding” and scaling that an attacker would have to conquer 2/3 of the shards to conquer the chain which is highly unlikely, but I am wondering what kind of attacks could occur on the beacon “coordinating” chain itself (which I assume is connected to “full-nodes”, not v-nodes)? Is it theoretically possible to conquer the “coordinator” or coordinating nodes/beacons rather than conquering the shards there altering potentially what the coordinator/beacon chain validates or fails to validate? Just curious here, I am a supporter of incognito, but thinking about the security of sharded blockchains is so much more complex than thinking about the security of a regular bitcoin-type single blockchain. Any explanations for the non-expert, layperson trying to get a handle on this would be appreciated.
To be clear, I am not asking about the diluted ambiguous terms “decentralization” and “centralization”, but about the risks / security issues associated with not having thousands of full-nodes running all over the planet. Given the incentives of p-nodes and v-nodes, it is clear we will have thousands of these running all over the planet.