I updated the BIP to cover only the specification of the transactions that need to be added. I will create a network BIP tomorrow. On Mon, Nov 10, 2014 at 11:42 AM, Tier Nolan wrote: > The aheaders message is required to make use of the data by SPV clients. > This could be in a separate BIP though. I wanted to show that the merkle > path to the aux-header transaction could be efficiently encoded, but a > reference to the other BIP would be sufficient. > > For the other messages, the problem is that the hash of the aux header is > part of the block, but the aux header itself is not. That means that the > aux header has to be sent for validation of the block. > > I will change it so that the entire aux-header is encoded in the block. I > think encoding the hash in the final transaction and the full aux-header in > the 2nd last one is the best way to do it. This has the added advantage of > reducing the changes to block data storage, since the aux-header doesn't > have to be stored separately. > > > On Mon, Nov 10, 2014 at 12:52 AM, Gregory Maxwell > wrote: > >> Some initial comments... >> >> Tying in the protocol changes is really confusing and the fact that >> they seem to be required out the gates would seemingly make this much >> harder to deploy. Is there a need to do that? Why can't the p2p part >> be entirely separate from the comitted data? >> >> On Mon, Nov 10, 2014 at 12:39 AM, Tier Nolan >> wrote: >> > I made some changes to the draft. The merkleblock now has the auxiliary >> > header information too. >> > >> > There is a tradeoff between overhead and delayed transactions. Is 12.5% >> > transactions being delayed to the next block unacceptable? Would adding >> > padding transactions be an improvement? >> > >> > Creating the "seed" transactions is an implementation headache. >> > >> > Each node needs to have control over an UTXO to create the final >> transaction >> > in the block that has the digest of the auxiliary header. This means >> that >> > it is not possible to simply start a node and have it mine. It has to >> > somehow be given the private key. If two nodes were given the same key >> by >> > accident, then one could end up blocking the other. >> > >> > On one end of the scale is adding a transaction with a few thousand >> outputs >> > into the block chain. The signatures for locktime restricted >> transactions >> > that spend those outputs could be hard-coded into the software. This >> is the >> > easiest to implement, but would mean a large table of signatures. The >> > person who generates the signature list would have to be trusted not to >> > spend the outputs early. >> > >> > The other end of the scale means that mining nodes need to include a >> wallets >> > to manage their UTXO entry. Miners can split a zero value output into >> lots >> > of outputs, if they wish. >> > >> > A middle ground would be for nodes to be able to detect the special >> > transactions and use them. A server could send out timelocked >> transactions >> > that pay to a particular address but the transaction would be >> timelocked. >> > The private key for the output would be known. However, miners who mine >> > version 2 blocks wouldn't be able to spend them early. >> > >> > >> > On Sat, Nov 8, 2014 at 11:45 PM, Tier Nolan >> wrote: >> >> >> >> I created a draft BIP detailing a way to add auxiliary headers to >> Bitcoin >> >> in a bandwidth efficient way. The overhead per auxiliary header is >> only >> >> around 104 bytes per header. This is much smaller than would be >> required by >> >> embedding the hash of the header in the coinbase of the block. >> >> >> >> It is a soft fork and it uses the last transaction in the block to >> store >> >> the hash of the auxiliary header. >> >> >> >> It makes use of the fact that the last transaction in the block has a >> much >> >> less complex Merkle branch than the other transactions. >> >> >> >> >> https://github.com/TierNolan/bips/blob/aux_header/bip-aux-header.mediawiki >> >> >> > >> > >> > >> ------------------------------------------------------------------------------ >> > >> > _______________________________________________ >> > Bitcoin-development mailing list >> > Bitcoin-development@lists.sourceforge.net >> > https://lists.sourceforge.net/lists/listinfo/bitcoin-development >> > >> > >