Public vs Permissioned Blockchains for Regulated Finance

Introduction: The L2 Approach to Institutional Compliance

As the GCC digital asset market matures, multiple infrastructure approaches are emerging to serve regulated institutions. Among them, ADI Chain represents an interesting L2 (Layer 2) model — building compliance infrastructure as a layer on top of existing blockchain networks rather than as a purpose-built L1 (Layer 1) chain. Understanding the L2 compliance model, its strengths, its architectural limitations, and how it compares to protocol-level L1 compliance is essential for institutions evaluating their infrastructure options.

The L2 approach to compliance operates on a fundamental premise: that it is more practical to add compliance to existing, proven blockchain infrastructure than to build a new chain from scratch. This premise has merit — existing L1 chains like Ethereum have been battle-tested with trillions of dollars in transaction value, have mature developer ecosystems, and have broad institutional recognition. Building compliance on top of this proven foundation potentially reduces technology risk compared to launching an entirely new chain. For more context, see Avalanche subnet architecture and protocol-level compliance infrastructure to understand how L1 compliance differs from L2 approaches.

However, the L2 approach also inherits the architectural constraints of the underlying L1 — constraints that may limit the compliance capabilities that can be achieved. This article examines the L2 compliance model through the lens of GCC institutional requirements, comparing it to the L1 protocol-level approach to identify where each model excels and where it falls short.

How L2 Compliance Works

An L2 compliance solution typically operates as a separate layer that sits between the institution and the underlying L1 blockchain. Transactions are submitted to the L2 layer, where compliance checks are performed — identity verification, sanctions screening, suitability assessment, transaction monitoring — before the transaction is forwarded to the L1 for execution and settlement.

This architecture provides compliance capabilities that the underlying L1 does not natively offer. The L2 can enforce KYC/AML requirements, implement jurisdiction-specific compliance rules, and generate audit trails — all without modifying the L1’s protocol or consensus mechanism. The institution interacts with the L2’s compliance-aware interface rather than directly with the L1’s permissionless environment.

The L2 model’s primary advantage is that it leverages the security, liquidity, and ecosystem of an established L1 while adding compliance capabilities. An L2 built on Ethereum, for example, benefits from Ethereum’s security guarantees, its deep liquidity pools, and its vast developer ecosystem. The compliance capabilities are added on top without requiring Ethereum itself to change.

The Bypass Problem: L2’s Fundamental Limitation

The L2 compliance model’s fundamental limitation is the same one that affects all application-layer compliance approaches: the underlying L1 does not enforce compliance. If a participant bypasses the L2 layer and interacts directly with the L1’s smart contracts — submitting transactions directly through the L1’s RPC endpoints, for example — the compliance checks that the L2 would normally perform are not executed.

This bypass vulnerability is not theoretical. Any participant with sufficient technical knowledge can interact with an L1 blockchain’s smart contracts directly, without going through any application or middleware layer. The L2’s compliance checks are only enforced for transactions that flow through the L2. Transactions that bypass the L2 and go directly to the L1 are processed by the L1 according to its own rules — which, on a permissionless chain, do not include identity verification, compliance screening, or suitability assessment.

For regulated institutions subject to FSRA, DFSA, or CBUAE supervision, this bypass vulnerability creates a compliance gap that regulators may question. If a regulator asks “can compliance be circumvented on your infrastructure?”, the honest answer for an L2 compliance model is “yes, if a participant interacts directly with the underlying L1 rather than through our compliance layer.”

Protocol-level L1 compliance addresses this vulnerability architecturally. On a purpose-built L1 where compliance is enforced at the protocol level — through precompiles, identity registries, and consensus-level transaction validation — there is no separate L1 to bypass. The chain itself rejects non-compliant transactions. The compliance enforcement and the transaction execution are performed by the same infrastructure, eliminating the architectural gap between the compliance layer and the settlement layer.

Stablecoin Integration: The AED Settlement Question

The L2 model’s relationship to stablecoins is an important consideration for GCC institutions. If the L2 operates on an L1 that uses a native cryptocurrency (ETH, for Ethereum L2s), participants may need to interact with that cryptocurrency for gas fees or other operational purposes — creating the token exposure that many institutional compliance policies prohibit.

Some L2 models address this by abstracting gas fees away from the institution, paying L1 gas costs internally and billing institutions in fiat. This approach reduces but does not eliminate cryptocurrency exposure — the L2 operator still holds and transacts in the L1’s native token, creating operational and potentially regulatory exposure that must be managed.

An L1 with zero native token — where gas is absorbed internally as an operating cost and all participant-facing economics are fiat-denominated — eliminates cryptocurrency exposure at every level. There is no L1 native token to hold, no gas fees to pay in cryptocurrency, and no operational exposure to volatile digital assets. The entire economic model is fiat-based from the institution’s perspective.

For AED-denominated settlement, the L2 model depends on the availability of CBUAE-licensed AED stablecoins on the underlying L1. If the L1 is Ethereum, AED stablecoins must be deployed on Ethereum and accessible through the L2’s compliance layer. An L1 designed for GCC compliance can accept AED stablecoins natively within its protocol, ensuring that AED settlement is an architectural capability rather than an integration dependency.

The Validator and Governance Question

L2 compliance solutions inherit the governance and validation model of their underlying L1. An L2 on Ethereum is ultimately secured by Ethereum’s proof-of-stake validators — a decentralized set of anonymous stakers with no regulatory accountability. If an Ethereum validator misbehaves, the consequence is token slashing — a financial penalty with no real-world regulatory or legal consequence.

For GCC regulators, the question of who validates and secures the infrastructure is relevant to regulatory classification and supervisory comfort. An L1 where validators are licensed institutions operating under FSRA or DFSA authorization — where misbehavior means removal from the validator set and reporting to the regulator — provides a governance model that aligns with GCC regulatory expectations. An L2 that inherits its security from anonymous L1 validators cannot offer this same regulatory alignment.

When L2 Compliance Works and When It Doesn't

The L2 compliance model works well for specific use cases: providing compliance capabilities for applications that must operate on established L1s for liquidity or ecosystem reasons, serving as a transitional solution for institutions that are not ready to commit to a purpose-built L1, and offering compliance tooling for developers building on existing infrastructure.

The L2 model falls short for institutions requiring architectural compliance guarantees that cannot be bypassed, for regulators seeking infrastructure where compliance enforcement is structurally inseparable from transaction execution, and for operational environments where zero cryptocurrency exposure is a binding constraint.

For GCC institutions evaluating their options, the choice between L2 compliance and L1 protocol-level compliance depends on whether the institution prioritizes access to existing L1 ecosystems (favoring L2) or architectural compliance guarantees and regulatory alignment (favoring purpose-built L1). Both models serve legitimate needs, but they serve them through fundamentally different architectural approaches with different strengths and different limitations.

Sources: ADI Chain documentation; Ethereum L2 ecosystem analysis; FSRA regulatory requirements; DFSA compliance frameworks; CBUAE PTSR 2024.