Background

To streamline operations and improve efficiency, the Beacon Chain was officially discontinued on Dec 3, 2024. This necessitates a process for users to recover their BEP2/BEP8 assets from the Beacon Chain to the BSC, where they will be represented as BEP20 tokens.

Note: only crosschain mirrored BEP2/BEP8 assets can be recovered, for details, please refer to https://docs.bnbchain.org/bc-fusion/users/assets/

The BEP2/BEP8 Token Recovery Feature

The Token Recovery feature would allow BEP2/BEP8 token holders to recover their tokens if they did not migrate their assets before the sunset of BNB Beacon Chain. This feature would be implemented through a smart contract that would allow users to submit a recovery request. The smart contract would then verify the user's identity and release the tokens to the user's new wallet address on BSC.

Proposed Solution

The proposed solution involves the following steps:

1. Snapshot: A final snapshot of all BEP2/BEP8 token holdings was taken at block height 385251927 on the Beacon Chain. This snapshot serves as the definitive record of ownership before the chain's shutdown.
2. TokenRecoverPortal: A dedicated web portal, the TokenRecoverPortal will be established to facilitate the token recovery process.

Tech Spec

After the Beacon Chain fusion, certain digital assets remain on the Beacon Chain. BEP-299 presents a secure and trustless solution for users to recover their Beacon Chain assets on the BSC.

Token Tree: A Merkle tree will be generated based on a snapshot of user balances on the Beacon Chain. This tree will be publicly auditable and verifiable. Only tokens with corresponding BNB/BEP20 tokens on BSC will be included.

Token Recover Portal:

• An Approval Server operated by the BNB Chain Foundation will verify user claims and issue approvals. The Approval Server serves as an additional security layer - even in the unlikely event of a Merkle proof algorithm compromise, it ensures the protocol's overall security remains intact.
• An Asset Claim Contract on BSC will process user claims, verify approvals, and unlock corresponding BNB/BEP20 tokens on BSC.

Process for Users:

1. Sign a message: Users sign a message with their BC account private key containing their address, token symbol, amount, and BSC receiver address.
2. Request approval: Users submit the signed message to the Approval Server.
3. Receive approval: The server verifies the claim and issues a signed approval with a Merkle proof.
4. Claim assets: Users submit the approval and proof to the Asset Claim Contract on BSC to receive their BNB/BEP20 tokens.
5. TimeLock: For security concerns, recovered funds on the BSC network are subject to a 7-day timelock period. After 7-days, tokens will automatically be transferred to the user's wallet without requiring any additional action.

This proposal aims to set the Merkle tree root and Approver wallet(used to sign approval) for the system contract. Once set, users can begin recovering their assets on BSC.

MerkleRoot = 0x1541b58c1301ebfb2b6ffe223ee72bea122f2a2aa36df1fa4801a4a135f9bc8e

Approver Wallet = 0x8b4596AF5FD12bac8D41BE7d7021aC7cE84fB590

Verify the Merkle root

• The Beacon Chain snapshot and Merkle tree data are publicly verifiable and accessible to all users.
  • - chaindata: https://pub-c0627345c16f47ab858c9469133073a8.r2.dev/bc-mainnet-dataseed.tar.gz
  • - asset proofs: https://pub-c0627345c16f47ab858c9469133073a8.r2.dev/bc-mainnet-proofs.tar.gz
• We offer a tool to verify asset proofs and the Merkle root. For detailed instructions, please refer to our documentation: https://github.com/bnb-chain/node-dump/blob/master/docs/verification.md