Long post: Why is it said that the index is the consensus layer of inscriptions?

Author: 0xmiddle

Index is a high-frequency term in the context of inscriptions. So what is an index? Why do inscriptions rely on indexes? What important significance does putting indexes on-chain have for inscriptions?

1. Friends who play with inscriptions must often hear the term "index." Whether it's project teams or technical experts, this term is frequently used in the context of inscriptions. What exactly is it? Why does the existence of inscriptions, aside from relying on blockchain, also depend on indexes?

2. What everyone needs to understand is that the essence of inscriptions is treating the blockchain as a hard drive, storing a new ledger in the "remark" field of existing transaction data, thus achieving the issuance of tokens. This ledger will not be verified or calculated by the blockchain itself.

3. If someone transfers an asset they do not actually own, or mints a token that has already been fully minted, this inscription will still go on-chain, but it is invalid. In other words, what is stored on the blockchain is a "dirty ledger," containing both valid and invalid data.

4. So who is responsible for identifying valid data and calculating each person's balance? This is the job of the "index." Of course, the index needs to operate based on a set of rules that have formed social consensus. For inscriptions, the blockchain is merely the data availability layer; the index is the real consensus layer.

5. If the index forks, then the consensus will fork, and the inscriptions will fork. Such situations can arise if various index service providers like wallets, browsers, and trading markets do not coordinate well during index upgrades or have disagreements over index rules.

6. BTC BRC20 inscriptions have experienced such situations multiple times. Last October, users discovered that major trading platforms were running different versions of the Ordinals indexer, with some inscriptions being indexed in the newer v0.9.0 but not in earlier versions, resulting in different balances for the same account displayed across different client applications. After coordination, all parties decided to standardize on v0.9.0 and freeze subsequent upgrades.

7. However, in January of this year, the turmoil resurfaced when the largest BRC20 wallet provider, Unisat, announced a unilateral update to the indexer, leading to the emergence of two different index rules in the market. In response to this event, the community split into different factions: some opposed the upgrade and favored freezing, some supported a cautious upgrade, and others advocated for coexistence through forking. What will happen next remains uncertain.

8. Now everyone understands that the index is the consensus layer of inscriptions. Moreover, this consensus is more of a social consensus. Social consensus is not necessarily solid, but during the upgrade process, it often goes through a prolonged tug-of-war and chaos before reaching a certain degree of "final certainty." This chaos may lead to asset losses for users.

9. Is there a way to convert social consensus into on-chain consensus? Intuitively, it seems not, because no inscription can require the underlying public chain to verify its validity. However, it seems we can take a different approach: what if we put the index rules on-chain? For example, what if we put the current consensus version of the Ordinals protocol on the BTC chain?

10. If this is done, there will be a unique valid index rule on-chain, and others can run effective and consistent final states based on on-chain data and rules. Of course, this cannot completely eliminate forks, as different stakeholders can still upload different versions of the index. But at the very least, this form would become a more effective coordination and confirmation mechanism, preventing chaos during the formation of social consensus.

11. The earliest proponent of this form is the permanent storage service provider AR, and this model is called the Storage Consensus Paradigm. It is said that AR's first inscription project, $ARIS, will use this mechanism to upload the index to AR, becoming the first "pure on-chain consensus" inscription.

12. I believe that the potential of the SCP paradigm goes far beyond inscriptions. It actually creates a brand new L2 model that is different from Rollup.

13. This model is more flexible than L2; it does not have to be in the form of a chain; it can take any form. For Web2 services, it can directly switch to Web3 services through the SCP method, gaining features like censorship resistance and immutability. Additionally, compared to the Rollup model, SCP shows more significant effectiveness in scalability, achieving resource efficiency at the Web2 level.

14. It seems that the SCP paradigm is theoretically the best path for large-scale migration of Web2 applications to Web3. I am optimistic about the "pure on-chain consensus inscriptions" that $ARIS is currently practicing, as they represent a transformation of the inscription paradigm. At the same time, I am hopeful for the future of SCP and look forward to more developers implementing the SCP paradigm, bringing more forms of applications into the Web3 ecosystem.