Yiyue Cao

Di Wu, Yuman Bai, Shoupeng Ren et al.

Centralized stablecoins such as USDT and USDC enforce financial sanctions through contract-layer blacklist functions, yet on public blockchains a freeze is merely an ordinary transaction that must compete for execution priority. We identify a fundamental gap between contract-layer authority and consensus-layer enforcement: when a sanctioned entity's transfer and the issuer's freeze race for inclusion in the same block, the outcome is determined not by regulatory mandate but by the economically motivated ordering decisions of block producers. We term the resulting value extraction Sanction-Evasion MEV (SE-MEV). To quantify this vulnerability, we construct the first comprehensive dataset of on-chain sanctions enforcement and evasion for Ethereum-based USDC and USDT (Nov 2017-Aug 2025), covering over $1.5 billion in frozen assets. We find that 7.3% of sanctioned USDT addresses and 18.7% of sanctioned USDC addresses were drained to zero balances before enforcement took effect, and document a clear escalation trajectory-from issuer-side out-of-gas failures, to public gas auctions, to private order flow, to direct proposer bribery. We further develop a game-theoretic model that yields three results: (i) compliant issuers cannot rationally stay outside the MEV market; (ii) fixed participation costs concentrate evasion among specialized, MEV-aware actors; and (iii) the implicit MEV tax extracted by block proposers grows without bound as regulatory penalties intensify, creating structural incentives for issuers to vertically integrate into block-building infrastructure. Our findings demonstrate that on any blockchain where ordering power is allocated by economic incentives, ordering power is sanctioning power-and contract-level authority alone cannot guarantee enforcement.

Yiyue Cao, Mingzhe Zheng, Lin William Cong et al.

Modern blockchain ecosystems comprise many heterogeneous networks, creating a growing need for interoperability. Cross-chain bridges provide the core infrastructure for this interoperability by enabling verifiable state transitions that move assets and liquidity across chains. While prior work has focused mainly on bridge design and security, the system-level and economic consequences of cross-chain liquidity interoperability remain less understood. We present a large-scale empirical measurement study of cross-chain interoperability using a dataset spanning 20 blockchains and 16 major bridge protocols from 2022 to 2025. We model the multi-chain ecosystem as a time-varying weighted hypergraph and introduce two complementary metrics. Structural interoperability captures connectivity created by deployed bridge infrastructure, reflecting bridge coverage and redundancy independent of user behavior. Active interoperability captures realized cross-chain usage, measured by normalized transfer activity. This decomposition separates infrastructure capacity from actual utilization and yields several findings. The cross-chain network evolves from a sparse hub-and-spoke structure into a denser multi-hub core led by EVM-compatible chains. Bridge expansion and chain growth are uneven: some chains achieve broad structural access but limited realized usage, whereas others concentrate activity through a small set of routes. Overall, interoperability provision and interoperability use diverge substantially, showing that connectivity alone does not imply economically meaningful integration. These results provide a measurement framework for understanding how cross-chain infrastructure reshapes blockchain market structure and liquidity organization.