Bitcoin is an innovative payment network and a new kind of money, and running your own node is how anyone can participate and verify for themselves. Large miners kept producing blocks that used transactions most nodes would not relay as a matter of policy. Following that chain means accepting use of the network for arbitrary data storage, which every node operator on that chain must store at their own expense and, most importantly, risk.
BIP-110, in alignment with the vast majority of node policy, attempted to reject use of the network for arbitrary data storage while leaving ordinary payments alone. That was a softfork: a tighter rule that old software can still follow, and it is not this hardfork. A hardfork is a break away from abuse of the Bitcoin network. Industrial mining firms blocked BIP-110 so they could keep selling block space for that use, then kept mining with those same transactions. Bitcoin with the BLAKE2b algorithm keeps Bitcoin as money only.
What you should do
- You do not need to move your bitcoin before the fork. Coins created before the fork remain spendable.
- If you use a hosted wallet or exchange, ask which chain they will credit after the hardfork.
- If you run your own node, upgrade before the hardfork and set the announced
blake2b_headline, which is a short phrase the first new-style block must include. - If you stay on Bitcoin Core or an older Bitcoin Knots release, you will follow a different blockchain. You need a Knots version with the BLAKE2b change, from bitcoinknots.org when it is published.
For common objections, see the FAQ. For the events that led here, see the release notes.