According to Wu Shuo, @spark_ren recently asked why RGB++’s CKB is considered BTC L2. CKB Lianchuang cipher explained that RGB++ is a client verification protocol that introduces an extension of Turing-complete programming to Bitcoin. RGB assets and state ownership are maintained and verified by the Bitcoin main chain, and CKB serves as the verification layer for scripts/contracts. Although both client verification and indexer verify the legality of new asset transactions, since RGB assets are attached to UTXO, only the relevant historical branches corresponding to UTXO need to be verified, without scanning and verifying global transactions like the indexer does, so it is relatively Lightweight.