Crossroads：用于链抽象资产的智能合约层

Jul 16, 2026

Crossroads introduces a smart contract layer for chain-abstracted assets, representing assets from nearly any blockchain as ERC-20 tokens on a single backend chain. This unified view enables smart-contract-based exchange, lending, and privacy applications within one platform, extending beyond traditional bridging by offering a general-purpose abstraction model. A threshold signing committee controls encumbered keys and signs backend transactions only as authorized by smart contracts. The system supports permissionless, modular integration via pluggable oracles, provides finalization guarantees, and supports optimistic access before finalization completes.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages18

Reading Time45 min

Abstract

Introduction

Cross-chain bridges and interoperability challenges

Hub-and-spoke limitations

Crossroads architecture and key encumbrance

Programmable cross-chain functionality

Crossroads: A Smart Contract Layer for Chain-Abstracted Assets James Austgen* Cornell Tech, IC3 [james@cs.cornell.edu](james@cs.cornell.edu) Dani Vilardell* Cornell Tech, IC3 [danivilardell@cs.cornell.edu](danivilardell@cs.cornell.edu) Ari Juels Cornell Tech, IC3 [juels@cornell.edu](juels@cornell.edu) arXiv :2607 .06525v 1 [ cs .CR] 7 Jul 2026 Abstract—This paper introduces Crossroads, a smart contract layer for chain-abstracted assets. In Crossroads, assets from nearly any chain are represented on a single backend blockchain as ERC-20 tokens. As a result, any asset can participate in smart-contract-based exchange, lending, or privacy applications on a single unified platform. So while Crossroads offers cross-chain bridging, a common, partial approach to alleviating the fragmentation of the blockchain ecosystem today, this is just one service within Crossroads’general-purpose chain-abstraction model. Crossroads relies on key encumbrance: a threshold signing committee holds encumbered keys controlling assets on each integrated chain, signing transactions only as authorized by smart contracts on the backend blockchain. Asset movements are fee-efficient, as ownership changes are recorded on the backend blockchain and users may set the transaction fee for withdrawals. Crossroads enables permissionless, modular integration of new blockchains using pluggable oracles with flexible design options (zkBridge, TEE-based, hybrid) . Asset deposits into Crossroads benefit from strong, chain-specific finalization guarantees, minimizing the risk of reorg attacks. Unlike existing bridges, however, third-party smart contracts in Crossroads can provide fast, optimistic access to funds before finalization completes. We prove that Crossroads satisfies soundness: given an honest quorum of signing committee members, any user can unilaterally generate a valid withdrawal transaction transferring their full net balance to an externally owned account on an integrated blockchain. We implement a proof of concept across multiple public blockchains: Bitcoin, Ethereum, and Solana. We catalog a range of applications enabled by Crossroads, including universal wallets, cross-chain staking and lending, privacy-preserving payments, and private management of public blockchain assets. 1. Introduction Cross-chain bridges are the main path today towards blockchain interoperability. Current bridges, though, generally only support a handful of high-liquidity chains or chains within a single family (EVM, Cosmos, Solana, Bitcoin, etc.) . Swaps between two cryptocurrencies often have to traverse * These authors contributed equally to this work. several cross-chain exchanges, e.g., an exchange of StarkNet ETH to Solana SOL, might involve three or more bridge operations and several intermediary token swaps [41] . The challenge is that a single bridge connects exactly two chains. Full pairwise connectivity is impractical, as supporting N chains would require N 2 bridges, each separately deployed and operated. Practical designs today therefore employ a sparse graph of bridges between high-liquidity chains, where transfers between unconnected chains must hop through intermediaries and pay fees at each step. A hub topology avoids such hopping: N connections make every pair of chains reachable through the hub, and N bridges are easier to audit than N 2. Existing hub-andspoke systems, however, fall short of this potential in three ways: integrating a new chain is a permissioned decision of the hub’s operators or governance; the hub’s functionality is fixed at the protocol level, typically transfers or swaps, rather than open to third-party applications; and integration generally requires verification logic on the connected chain itself, leaving chains without smart contracts, such as Bitcoin, behind. Crossroads. In this work, we present Crossroads, a smart contract layer for chain-abstracted assets. Crossroads adoptsa hub-and-spoke topology but,

FAQs

Crossroads如何把不同链上的资产统一到同一个系统里？

Crossroads将几乎任何链上的资产映射为后端区块链上的ERC-20代币。后端链上的智能合约即可对这些代币执行交换、借贷等操作，从而实现跨链资产的统一交互。

Crossroads的密钥如何被控制以保障资产安全？

系统依赖阈值签名委员会持有“受限密钥”。委员会仅在后端链上的智能合约授权时才对交易进行签名，从而控制各接入链上的资产相关操作。

Crossroads如何实现从后端链到原生链的提现流程？

用户在后端链上先销毁对应的ERC-20代币。委员会验证该销毁与资产合约一致后，为用户选择的地址签发转账交易，且用户可设置提现费用并决定广播时机。

Jul 16, 2026

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