I created a genesis.json initial_key using very helpful instructions from gensis.json initial key parameter: what is it?.
My question - does the initial key have any crypto significance or is it simply a hash for nodes to verify if they are properly on the same network?
Do I need to keep the private key generated for the initial_key safe? Does it have any use?
When you starts a fresh blockchain with genesis.json, system account eosio is automatically generated with initial_key. eosio is the only one BP in this environment, and the signing key for block production becomes the given initial_key.
If you change initial_key, you also need to change the signing key used by nodeos when it produces a block. You can find signature-provider option from config.ini of nodeos. You can run nodeos like nodeos --signature-provider=EOS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV=KEY:5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3 instead of putting this into config.ini.
Did some testing trying to make the initial_key something completely different than the initial signature-provider keypair and nodeos started throwing the following errors:
error 2020-06-06T07:36:25.001 nodeos producer_plugin.cpp:1457 start_block ] Not producing block because I don't have any private keys relevant to authority: [0,{"threshold":1,"keys":[{"key":"EOSRandomInitialKey","weight":1}]}]
So through my initial findings, yes - that key is significant otherwise subsequent blocks cannot be added.
I'd still love for someone to answer the why or how it works.