Our Focus

The EEA Crosschain Interoperability Working Group is dedicated to standardising one of the most important areas in blockchain: crosschain communications. The Working Group is focused on enabling code and nodes on a blockchain to call code deployed on a different blockchain, and where appropriate, receive a response. The working group is responsible for developing technical standards to meet this challenge. Its work includes: a) creating a conceptual framework that enables sound reasoning about this topic, b) identifying salient technical and security challenges that inform the design space, and c) defining a protocol architecture and an associated set of specifications through which to drive standardization and broad adoption.

We define crosschain interoperability as the ability to transfer assets from one blockchain to another blockchain, the ability to send and receive messages across blockchains, and the ability to initiate actions across blockchains. Though crosschain systems often involve just two blockchains, crosschain interoperabiity allows for more complex scenarios involving multiple blockchains. We expect that our specifications will work in the context of public Ethereum blockchains, consortium blockchains, optimistic rollups, zk rollups, non-Ethereum Virtual Machine blockchains and other blockchain-like systems.

Resources

Published EEA Documents


Crosschain Interoperability Use Case

[eeaciw-crosschainusecasesv1.0] EEA CIW - Crosschain Interoperability Use Case Version 1.0. Edited by Weijia Zhang and Peter Robinson. 04 June 2020. EEA CIW. https://entethalliance.github.io/crosschain-interoperability/CIFT_Use_Case.pdf. Latest stage: https://entethalliance.github.io/crosschain-interoperability/CIFT_Use_Case.pdf .

Crosschain Security Guidelines

[eeaciw-crosschainsecurity-v1.0] EEA CIW - Crosschain Security Guidelines Version 1.0. Edited by Weijia Zhang, Peter Robinson and Aiman Baharna. 24 September 2021. EEA CIW. https://entethalliance.github.io/crosschain-interoperability/crosschainsecurityguidelines.html. Latest stage: https://entethalliance.github.io/crosschain-interoperability/crosschainsecurityguidelines.html .

Crosschain Decentralization Guidelines

[eeaciw-crosschaindecentralization-v1.0]EEA CIW - Crosschain Decentralization Guidelines Version 1.0. Edited by Weijia Zhang, Peter Robinson and Aiman Baharna. September 2022. EEA CIW. https://entethalliance.org/specs/crosschain-decentralization/v1/. Latest stage:https://entethalliance.org/specs/crosschain-decentralization/v1/



Documents in Development


Crosschain Identification Specification

[eeaciw-crosschainidentification-v1.0] EEA CIW - Crosschain Identification Specification Version 1.0. Work in Progress. Edited by Weijia Zhang and Peter Robinson. 14 December 2020. EEA CIW. https://entethalliance.github.io/crosschain-interoperability/crosschainid.html

EIP-3220: Crosschain Identifier Specification

[eeaciw-eip-3220-v1.0] EIP-3220: Crosschain Identifier Specification. Work in Progress. Authored by Weijia Zhang and Peter Robinson. 21 October 2020. EEA CIW. https://eips.ethereum.org/EIPS/eip-3220 .

Crosschain Interoperability Specification

[eeaciw-crosschainspec-v1.0] EEA CIW - Crosschain Interoperability Specification Version 1.0.
Edited by Peter Robinson, Weijia Zhang, and Aiman Baharna.
Draft specification.

Crosschain Messaging Interfaces

[eeaciw-crosschainmessaging-v1.0] EEA CIW - Crosschain Messaging Interfaces Version 1.0.
Edited by Peter Robinson, Weijia Zhang, and Aiman Baharna.
Draft specification.

Crosschain Function Call Interfaces

[eeaciw-crosschainfunctioncall-v1.0] EEA CIW - Crosschain Function Call Interfaces Version 1.0.
Edited by Peter Robinson, Weijia Zhang, and Aiman Baharna.
Draft specification.



Educational Videos


Token Economics & Blockchain Security

Tokenization IG x Crosschain Interop WG: Token Economics & Blockchain Security. Presented by Benjamin Bukari and Weijia Zhang. 13 September 2022. https://www.youtube.com/watch?v=alyjDpDcHj4 .

Crosschain asset transfer for Non-Fungible Tokens

Crosschain asset transfer for Non-Fungible Tokens. Presented by Weijia Zhang. 22 June 2022. https://www.youtube.com/watch?v=3U4fFHcT7Lc .

Crosschain Applications using Crosschain Protocol Stack & GPACT

Crosschain Applications using Crosschain Protocol Stack & GPACT. Presented by Peter Robinson. 01 June 2022. https://www.youtube.com/watch?v=zORcdGcB3so .

Transferring Value to and from the Ethereum Mainnet and Other Cross-Chain Interactions

Transferring Value to and from the Ethereum Mainnet and Other Cross-Chain Interactions. Presented by Weijia Zhang and Peter Robinson. 18 October 2021. EEA CIW. https://www.youtube.com/watch?v=oAGO5PsyG0I .

Blockchain / Crosschain / DeFi Bridge Design

Blockchain / Crosschain / DeFi Bridge Design. Presented by Peter Robinson. 13 October 2021. EEA CIW. https://www.youtube.com/watch?v=zq4cbS3q-lY .

General Purpose Atomic Crosschain Transactions (GPACT)

General Purpose Atomic Crosschain Transactions (GPACT). Presented by Peter Robinson. 03 February 2021. EEA CIW. https://www.youtube.com/watch?v=ixK0_ltjr8k .



Blog


The Demands for Cross-chain Transactions Between Ethereum and Other Blockchains Have been Soaring.

The Demands for Cross-chain Transactions Between Ethereum and Other Blockchains Have been Soaring.. Motoki Yoshida, Datachain Inc. 26 May 2022. https://entethalliance.org/the-demands-for-cross-chain-transactions-between-ethereum-and-other-blockchains-have-been-soaring/ .

Unlocking the Next Steps in Crosschain Interoperability

Unlocking the Next Steps in Crosschain Interoperability. EEA Crosschain Interoperability WG. 17 May 2022. https://entethalliance.org/unlocking-the-next-steps-in-crosschain-interoperability/ .

Chain Reaction: The Insanity of L1 Bridges (Cross-Chain Chaos)

Chain Reaction: The Insanity of L1 Bridges (Cross-Chain Chaos). Andreas Freund. 08 February 2022. https://entethalliance.org/chain-reaction-the-insanity-of-l1-bridges-cross-chain-chaos/ .

How to Contribute

For information on how to join the group, see contact below:

Specifications & Guidelines Development

The working group collaborates to develop a set of specifications and guidelines that defines requirements for implementations (clients, bridges etc) enabling crosschain interoperabiity. You can contribute by joining and getting involved in our bi-weekly calls and by writing, reviewing and providing feedback on draft specifications.

Code and Test Suite:

If you are a developer, you can particpate by contributing to the development of the different interfaces of the Crosschain Protocol Stack. The Crosschain Protocol Stack defines a way for enterprises to create interoperable components for crosschain communications.

Chair

Contact Us

Non-EEA Members:

If you are interested in the work of the EEA Crosschain Interoperability WG and would like to contribute, please contact : james.harsh@entethalliance.org .

EEA Members:

Please contact the EEA Secretariat or your member council representative.