IOTA is a crowdfunding project in 2014. The purpose is to use DAG (Directed Acyclic Graph, called Tangle in IOTA) instead of blockchain to achieve distributed and irreversible, based on which integrated cryptocurrency functions are integrated to serve the Internet of Things. The DAG-based design does not have the concept of blocks, and the expansion is not limited by the block size. Its scalability depends on the limitations of network bandwidth, CPU processing speed, and storage capacity.
Because the current computing power of the entire IOTA network is extremely low (usually around 1 ~ 2TPS, which can be achieved by a good computer), the transaction confirmation of the current IOTA network does not use the inherent characteristics of the tangle but uses "Coordinator". When the coordinator works, transactions are issued by a specific address. The transactions issued by this address are unconditionally accepted by the entire network. It is solidified in the code of all IOTA nodes. The confirmation of the entire network is the responsibility of the coordinator. In addition, DAG technology has no advantage in network transaction propagation. All nodes still need to receive all transaction information through broadcast. Therefore, the infinite expansion of IOTA and the nature of the block system to relax the block size It's the same.
Advantages: It is free of transaction. The more effective transactions, the more reliable the system is, and it supports offline transactions.
Disadvantages: It is vulnerable to DOS attacks, and it is prone to double spend problems. An address can only be used once.
Although DAG is a very new and promising technology, the IOTA network based on it is still in the laboratory stage.