seems that the miner would have to basically do "extra work". and if there's no reward from the bitdns mining from the extra work (which of course, slows down the main bitcoin work), what would be a miner's incentive to include bitdns (and whatever other side chains) ?
The incentive is to get the rewards from the extra side chains also for the same work.While you are generating bitcoins, why not also get free domain names for the same work?
If you currently generate 50 BTC per week, now you could get 50 BTC and some domain names too.
You have one piece of work. If you solve it, it will solve a block from both Bitcoin and BitDNS. In concept, they're tied together by a Merkle Tree. To hand it in to Bitcoin, you break off the BitDNS branch, and to hand it in to BitDNS, you break off the Bitcoin branch.
In practice, to retrofit it for Bitcoin, the BitDNS side would have to have maybe ~200 extra bytes, but that's not a big deal. You've been talking about 50 domains per block, which would dwarf that little 200 bytes per block for backward compatibility. We could potentially schedule a far in future block when Bitcoin would upgrade to a modernised arrangement with the Merkle Tree on top, if we care enough about saving a few bytes.
Note that the chains are below this new Merkle Tree. That is, each of Bitcoin and BitDNS have their own chain links inside their blocks. This is inverted from the common timestamp server arrangement, where the chain is on top and then the Merkle Tree, because that creates one common master chain. This is two timestamp servers not sharing a chain.
I think it would be possible for BitDNS to be a completely separate network and separate block chain, yet share CPU power with Bitcoin. The only overlap is to make it so miners can search for proof-of-work for both networks simultaneously.
The networks wouldn't need any coordination. Miners would subscribe to both networks in parallel. They would scan SHA such that if they get a hit, they potentially solve both at once. A solution may be for just one of the networks if one network has a lower difficulty.
I think an external miner could call getwork on both programs and combine the work. Maybe call Bitcoin, get work from it, hand it to BitDNS getwork to combine into a combined work.
Instead of fragmentation, networks share and augment each other's total CPU power. This would solve the problem that if there are multiple networks, they are a danger to each other if the available CPU power gangs up on one. Instead, all networks in the world would share combined CPU power, increasing the total strength. It would make it easier for small networks to get started by tapping into a ready base of miners.
The networks wouldn't need any coordination. Miners would subscribe to both networks in parallel. They would scan SHA such that if they get a hit, they potentially solve both at once. A solution may be for just one of the networks if one network has a lower difficulty.
I think an external miner could call getwork on both programs and combine the work. Maybe call Bitcoin, get work from it, hand it to BitDNS getwork to combine into a combined work.
Instead of fragmentation, networks share and augment each other's total CPU power. This would solve the problem that if there are multiple networks, they are a danger to each other if the available CPU power gangs up on one. Instead, all networks in the world would share combined CPU power, increasing the total strength. It would make it easier for small networks to get started by tapping into a ready base of miners.
And Odalv comes through with the backbreaker once again
That is a fantastic insight from Satoshi on MM and quite interesting that he had coined the term "sidechains" already. Thank you for pulling this up