Draft: Introducing an multi tier blockchain that allows high transaction processing without compromising decentralisation

[Arcurus 331]

Hi all,

here is a draft how we could use an multi tier blockchain that allows high transaction processing without compromising decentralisation.

As always feels welcome to give feedback,

Arcurus

 

This proposal is based on this proposal, so good to read this first:

 

How could a multi tier block chain look like:

- the normal block would be called zero tier block

- a block in the next tier is called tier one block

- a block in the next tier after tier one is called tier two block

- each tier block references the next tier

- higher tiers could have increased block size and or faster block creation or other useful properties

- the output of tier x transactions is marked to be spent by all according to the tier x-1 logic

- so called manifestation transactions see above could be used to summarize what was happening in the higher tiers.

 

What are the benefits?

Though using a multi tier block chain architecture we would have the possibility to use different tiers for different purposes. Currently we face the problem that one single tier block chain cannot solve two contradicting properties like decentralizations vs transaction throughput. Naturally it can only be good according to one of these properties, or must compromise these properties. In a multi tier block chain, tier zero could be used to have good decentralization properties while an higher tear could be used to have an high transaction throughput. Naturally transactions in an higher tear would be less safe, but would be also less expensive. In short the more you pay the higher likely the tear your transaction is included and the more secure your transaction will be.

 

Can this be implemented as on soft fork?

Yes, this could be implemented as a soft fork the same way as outlined above in extended blocks.

[Arcurus 331]

UPDATE:

old nodes that are not aware of an higher existing tier can just continue to validate transactions as they always did. Updated nodes, that are aware of an higher tier, but do not have enough resources to be a full node on a higher tier, could if they want take part in the active enforcement of higher tear transactions in the following way:

- they could download the full or a part of the current balances (unspent set) from higher tier nodes and block transactions / blocks that are not valid according to that

- if they dont have the current balances they could ask higher tier nodes if the transaction is valid and block if not

 

What is the trust model for that?

At worst it would have the same trust model as now, because also now miners have the power to block transactions as long as a majority of the mining power agrees.

Further the following could be done to increase the security:

- lower tier nodes could verify, that the balance set is referenced from an block in the longest chain and therefore has at least the majority of the miners behind it

- lower tier nodes could partially proof the validity of the balances and could denounce nodes that provide invalid data 

- lower tier nodes could ask different higher tier nodes they trust if they agree on the current balances or validity of an higher tier transaction