2017-08-28 19:12 GMT+02:00 Gregory Maxwell via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org>: > > The bits field can only change every 2016 blocks (4 bytes per header), > the timestamp can not be less than the median of the last 11 and is > usually only a small amount over the last one (saves 2 bytes per > header), the block version is usually one of the last few (save 3 > bytes per header). > ... and I guess the nonce can be arbitrarily truncated as well, just brute force the missing bits :-P. > But all these things improvements are just a constant factor. I think > you want the compact SPV proofs described in the appendix of the > sidechains whitepaper which creates log scaling proofs. > I think that my blog post on compact spv proofs can be helpful also. It tries to make the pretty compact formulations in the sidechains paper a bit more graspable by normal people. http://popeller.io/index.php/2016/09/15/compact-spv-proofs/ Kalle