I wanted to know what are advantages and disadvantages of DAG over Blockchain ?
I'm answering on the context of Iota Advantages
- Best suited for micro-transactions because it's not worth paying someone 0.5$ if transaction fee is 1$.
- Scales infinitely at least theoretically, as the size of the network increases, the speed increases too.
- It removes the need for miners, making system more decentralized otherwise large mining pools can take over or influence the network.
- Iota implementation is also quantum resistant.
- Needs a lot of traffic before it can start operating.
- Decrease in network traffic renders network vulnerable to attacks.
- Coordinators used for kick-starting look fishy to the community.
I'll update as I find more interesting points to add.
Directed Acyclic Graph (DAG) coins. IOTA’s Tangle, Byteball, and Raiblocks are examples. They’re gaining a lot of traction as they seem to be a really awesome alternative to the blockchain.
RaiBlocks uses a block-lattice structure. Each account has its own blockchain (account-chain), equivalent to the account's transaction/balance history. Each account-chain can only be updated by the account's owner; this allows each account-chain to be updated immediately and asynchronously to the rest of the block-lattice, resulting in quick transactions. Since blocks can only be added by each account-chain's owner, transferring funds from one account to another requires two transactions: a send transaction deducting the amount from the sender's balance and a receive transaction adding the amount to the receiving account's balance.
Each individual transaction is a block, and each block is able to be processed instantly by the network. It secures its ledger via delegated proof of stake. They pre-cache the anti-spam Proof of Work for the next transaction once a transaction is sent, making transactions instantaneous, as both sides have the proof of work ready to go.
Instead of each block having many separate transactions, RaiBlocks reduces this by everytime a new tx is formed, it absorbs the tx behind it reducing the size of the block. So rather than having a maze of tx like Bitcoin, RaiBlocks stores the values of accounts instead.