Vitalik: I'm pleased to see Arbitrum has implemented the first phase of Rollup

Ethereum co-founder Vitalik posted on Warpcast, expressing his pleasure to see that a Rollup has entered the first phase this year (and several projects are very close to the first phase). This is real decentralized progress, and he hopes to see ten Rollups enter the first phase next year and achieve a certain degree of sequencer decentralization. From the screenshot posted by Vitalik, it can be seen that the Rollup he referred to as entering the first stage is Arbitrum. According to Vitalik's preliminary proposal at Ethereum Magicians forum, L2beat subsequently summarized and organized the phased development definition of Rollup. Compared with Phase 0, a Phase 1 Rollup must meet five conditions: 

1. A complete and fully functional proof system has been deployed; 
2. At least 5 external participants can submit fraud proofs;
3. Users can exit without needing assistance from authorized operators;
4. If more centralized participants than Security Council implement unnecessary upgrades, users have at least seven days to exit;
5. The Security Council is properly established.