Briefing
The core research problem is the unquantified risk of Maximal Extractable Value (MEV) in Directed Acyclic Graph (DAG) consensus architectures, which prioritize high throughput over the sequential ordering inherent to traditional blockchains. The foundational breakthrough is the formal identification and analysis of three distinct frontrunning attack vectors ∞ the DAG-Sandwich, the DAG-Reorder, and the DAG-Inclusion attack ∞ that exploit the concurrent block proposal and causal history structure unique to DAGs. This new theory implies that the pursuit of superior scalability via DAGs introduces a new class of complex, architecture-specific MEV vulnerabilities, fundamentally challenging the security-throughput trade-off for next-generation decentralized systems.
Context
Prior to this work, MEV analysis focused predominantly on sequential, leader-based blockchain models, where frontrunning is primarily a race for block inclusion or ordering within a single canonical block. DAG-based consensus, adopted by protocols for its superior throughput and low latency, was assumed to naturally mitigate some MEV risk due to its concurrent block production and multi-leader structure. The prevailing theoretical limitation was a lack of formal models and empirical evidence to quantify how the non-linear, partial ordering of transactions in a DAG structure could be exploited for profit.
Analysis
The paper’s core mechanism is the conceptual mapping of traditional MEV strategies onto the DAG’s unique transaction ordering structure, which is defined by the causal history of blocks. The breakthrough identifies three new attack primitives. The DAG-Sandwich Attack exploits the gap between a transaction’s inclusion in a block and its final execution, allowing an attacker to insert transactions before and after the victim’s within the same execution sequence by manipulating the DAG’s anchor block selection. The DAG-Reorder Attack leverages the multi-leader environment to bribe or coerce multiple concurrent block producers to agree on a specific, profitable transaction ordering within the final execution sequence.
The DAG-Inclusion Attack is a generalized denial-of-service vector where an attacker ensures a profitable transaction is included while preventing a competing transaction from ever entering the finalized DAG structure. This fundamentally differs from sequential models by exploiting the concurrency of block proposals, rather than the singular sequence of a single block proposer.
Parameters
- Novel Attack Primitives Identified ∞ Three. The number of unique, architecture-specific frontrunning strategies (DAG-Sandwich, DAG-Reorder, DAG-Inclusion) formally proven to exploit DAG-based consensus models.
Outlook
This research mandates a fundamental shift in how decentralized systems approach MEV mitigation, moving beyond simple block-based solutions to architecture-aware mechanism design. The next steps will involve developing formal proofs for DAG-native fairness protocols, such as encrypted mempools or time-delay puzzles that account for concurrent block production. In 3-5 years, this work will directly inform the security model of high-throughput protocols, leading to a new generation of DAG-BFT consensus mechanisms that integrate provable fairness directly into their block-selection and transaction-ordering logic, thereby unlocking truly scalable and secure decentralized finance applications.
Verdict
The formalization of DAG-native MEV vectors proves that high-throughput consensus mechanisms must fundamentally re-engineer transaction ordering to achieve foundational fairness and security.
