On Fri, Dec 11, 2015 at 11:18 AM, Jorge Timón <jtimon@jtimon.cc> wrote:

This is basically what I meant by

struct hashRootStruct
{
uint256 hashMerkleRoot;
uint256 hashWitnessesRoot;
uint256 hashextendedHeader;
}

but my design doesn't calculate other_root as it appears in your tree (is not necessary).

It is necessary to maintain compatibility with SPV nodes/wallets.

Any code that just checks merkle paths up into the block header would have to change if the structure of the merkle tree changed to be three-headed at the top.

If it remains a binary tree, then it doesn't need to change at all-- the code that produces the merkle paths will just send a path that is one step deeper.

Plus, it's just weird to have a merkle tree that isn't a binary tree.....

--
Gavin Andresen