Because someone needs to show you a valid set of transitions in the PKI from the original keys in the genesis block to the current attacker controlled PKI.
If the corresponding private key of a public key in the genesis block defines the correct transaction history then this system is not decentralized, but controlled by whoever owns this private key. In which case this entity might as well just sign blocks to avoid the double spend problem in a much simpler (albeit centralized) way.
I prefer if people differentiate between systems with a PKI and systems without a PKI.
Systems without a PKI like PoW or PoET can be rather centralized like Bitcoin today or decentralized like Bitcoin before the emergence of mining pools.
Systems with a PKI can have an onchain PKI like Cosmos. One of the challenges in an on chain PKI system is you need some of kind social pre-consensus on launch. The crowdfunding established an part of an initial pre-consensus but there are more moving pieces coming.
It's not a single private key. There are a lot of validators, even in the genesis block, and we assume that at least 2/3 of these validators are honest.
runeks|8 years ago
zmanian|8 years ago
Systems without a PKI like PoW or PoET can be rather centralized like Bitcoin today or decentralized like Bitcoin before the emergence of mining pools.
Systems with a PKI can have an onchain PKI like Cosmos. One of the challenges in an on chain PKI system is you need some of kind social pre-consensus on launch. The crowdfunding established an part of an initial pre-consensus but there are more moving pieces coming.
sunnya97|8 years ago