Subject: [bitcoin-dev] Uniquely identifying forked chains

From: gladoscc <[email-masked]>
Date: Sat, 29 Aug 2015 01:27:01 +1000

There has been discussion of using the genesis block hash to identify
chains in BIP 21 (bitcoin:// URI scheme). However, this does not allow
identification between blockchain forks building upon the same genesis
block. While many see this as undesirable, I think it is inevitable that
this will eventually happen at some point, and think it is best to build
systems redundantly.

I propose identifying blockchains for BIP 21 and any other relevant needs
through:

1) the genesis block hash for a new chain, or
2) a hash of the genesis block hash,  concatenated with block hash(es) of
fork point(s) for a fork chain

This would support forks, forks of forks, forks of forks of forks, etc
while preserving a fixed length chain identifier.

If a user wants to specify "whatever chain is the longest with PoW", they
would use (1). In times where multiple chains are coexisting and being
actively mined, a user can use (2) to specifically identify a chain.

Thoughts?