Scalability of Blockchain vs DAG based Cryptocurrency

When I was considering the ground design of my cryptocurrency's architecture, I planed to adopt DAG ledger. And I've thought a lot about it. This time I'll write about the merit and demerit.

New Technology?

Byteball and IOTA are famous cryptocurrency which is implemented with DAG.They don't use blockchain.

The goal of using DAG is scalability of transaction processing speed.

Most of people think DAG is one of solution to improve blockchain's weak point.

Actual Merit of DAG

To think DAG is to make parallel computing possible, is not accurate. That's because DAG is just data format, like blockchian.

The blockchain is serialized storage, therefore it can't add data simultaneously. But DAG is not serialized, therefore the system can add data simultaneously.

Demerit of DAG

Demerit of DAG is that it does not has method to make consensus of data on P2P nodes. Therefore DAG ledgers needs additional mechanism for consensus.

It is usually realized by centralized node or limited number of nodes. DAG ledger is not good at decentralization.

How to Scale Blockchain

There are certain number of people who thinks blockchain is not good at transaction scalability. That's because

• A. Blockchain is serialized storage, and the size is limited
• B. Blockchain needs heavy nonce calculation for perfect decentralization

About problem A, I think sharding blockchain is the solution.

About B, I think nonce calculation is not always necessary. General PoS(Proof of Stake) algorithm is weak at decentralization, because distribution of the coins is not fair.

But I think weak point of PoS is improvable. I'll write about Ticket PoS using least nonce calculation, next.