Why is it said that the index is the consensus layer of the inscription?

Author: 0xmiddle

Friends who play inscriptions must often hear the term "index." Whether from project parties or technical experts, this term is frequently used in the context of inscriptions. What exactly is it? Why does the existence of inscriptions rely not only on the blockchain but also on indexing?

What we need to understand is that the essence of inscriptions is treating the blockchain as a hard drive, storing a new ledger in the "memo" field of the existing transaction data, thereby enabling the issuance of tokens. This ledger will not be verified or calculated by the blockchain itself.

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

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 must operate according to a set of rules that have formed a social consensus. For inscriptions, the blockchain is merely the DA layer, while the index is the true consensus layer.

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

The Bitcoin BRC20 inscriptions have experienced this situation multiple times. In October last year, users discovered that major exchanges were running different versions of the Ordinals indexer, with some inscriptions being indexed in the newer v0.9.0 but not in earlier versions, leading to inconsistent balance displays for the same account across different clients. After coordination, it was decided to standardize on v0.9.0 and freeze subsequent upgrades.

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

Now we understand that the index is the consensus layer of inscriptions. Moreover, this consensus is more of a social consensus. Social consensus may not necessarily be fragile, but during the upgrade process, it often undergoes prolonged struggles and chaos before achieving a certain degree of "final certainty." This chaos may lead to asset losses for users.

Is there a way to transform social consensus into on-chain consensus? Intuitively, it seems there isn't, because no inscription can require its underlying public chain to verify its validity. However, we might find an alternative approach: what if we also put the index rules on-chain? For example, what if we place the current consensus version of the Ordinals protocol on the Bitcoin chain?

If we do this, there will be a uniquely valid index rule on-chain, and anyone can run an effective and consistent final state based on on-chain data and rules. Of course, this does not completely eliminate the possibility of forks; 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, avoiding the chaos in the formation process of social consensus.

The earliest proponent of this form is the permanent storage service provider Arweave, and this model is referred to as the Storage-Based Consensus Paradigm (SCP). It is said that Arweave's first inscription project, $ARIS, will adopt this mechanism, uploading the index to Arweave and becoming the first "pure on-chain consensus" inscription.

The author believes that the potential of the SCP paradigm goes far beyond inscriptions. It actually creates a brand new L2 model that is distinct from Rollup.

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

Currently, it seems that the SCP paradigm is the best path for large-scale migration of Web2 applications to Web3. The author is optimistic about the "pure on-chain consensus inscriptions" that $ARIS is practicing, as they represent a transformation in the inscription paradigm. At the same time, the author is hopeful about the prospects of SCP and looks forward to more developers implementing the SCP paradigm, bringing more forms of applications into the Web3 ecosystem.