Crosschain NFTs: A Wanchain Bridge Upgrade

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Wanchain

5 min readOct 27, 2022

TL;DR Wanchain bridges add crosschain NFT transfers. Crosschain NFT transfers are now live on Wanchain, Ethereum, XDC Network, BNB Chain & Polygon!

NFTs, or non-fungible tokens, are distinguishable assets that can be used to represent ownership. Earlier this year, NFTs, largely representing ownership of digital art pieces, fully captured the peoples’ imaginations and NFTs are now a fundamental component of the mainstream audience’s understanding of blockchain technology itself. And though the initial wave of excitement has subsided — partly due to the overall market conditions — NFTs are clearly here to stay.

Until now, the only way to move NFTs from the confines of a single chain or marketplace was to rely on centralised solutions. This is no longer the case!

Beginning today, users can use Wanchain’s industry-best crosschain bridges to execute decentralised, non-custodial NFT crosschain transaction between Wanchain, Ethereum, XDC Network, BNB Chain & Polygon!

What are crosschain NFTs?

Crosschain NFTs are NFTs that can move between multiple blockchain networks. Crosschain NFT transactions are executed using Wanchain crosschain bridges.

How do crosschain NFTs work?

Wanchain’s crosschain NFTs use a variation of the lock-mint-burn-unlock (LMBU) mechanism that Wanchain itself pioneered. As a quick reminder, when using the LMBU method, the NFT on the source chain is locked before a mirrored copy is minted on the destination chain. To unlock the original NFT, the mirrored NFT must first be destroyed, or burned.

Unlike fungible tokens like $USDT, most NFTs have attributes. These can add both functionality and additional uniqueness to NFTs. Wanchain bridges preserve NFT attributes during the crosschain process. In other words, when a mirrored copy of an NFT is minted on the destination chain, the mirrored copy has the same attributes as the original NFT.

What kinds of NFTs are crosschain compatible?

Wanchain’s NFT bridges support both ERC721 and ERC1155 standards, as well as chain-specific variants. Once a collection is registered, all individual NFTs can use the bridge. Individual NFTs do not need to be registered.

NFT crosschain transactions are executed using the same secure multi-party computation (sMPC) architecture that distinguishes Wanchain’s interoperability solutions. Single NFT and bulk transactions are supported.

What specific NFT collections are supported?

Crosschain NFTs have several advantages over NFTs that are confined to a single blockchain network. Not only does being crosschain-compatible expose an NFT to more communities and marketplaces, crosschain NFTs enable novel innovative novel use cases. For example, a gamefi platform like ZooGames could use the same NFT in multiple games on multiple chains.

The first wave of crosschain-compatible NFTs, include:

DØP3 Club NFT (XDC Network, Ethereum, BNB Chain, Polygon)
ZooGenes (Wanchain, Ethereum)

Additionally, full support for the following marketplaces include:

XDCNFT
XDSEA

These will be added to Wanchain bridges on a rolling basis over the coming days.

How to complete a crosschain NFT transaction?

1 — Go to WanBridge and select the “NFT Crosschain” tab.

2 — Select a collection from the dropdown menu.

3 — Select the From and To chains. These correspond to the source and destination chains.

4 — Input the recipient address.

5 — Click “Select your NFT.” A pop-up window will appear allowing you to select one or more NFTs.

6 — In situations where more than 1 of the same NFT exists (as is the case the ERC1155 NFTs), you can toggle how many to send in a single transaction. Remember, Wanchain bridges support both single NFT and bulk transactions.

7 — Confirm your selections and initiate the crosschain trainsaction.

Anything else?

There is some variance in how different marketplaces and project teams design their NFTs. Technically, an NFT collection corresponds to a particular NFT smart contract. Oftentimes, a marketplace may present a group of NFTs to an end user as a unique collection. However, this same marketplace may use a single smart contract to deploy all their collections while storing some identifying information off chain. In such a scenario, all the “collections” deployed by this marketplace are technically all part of the same collection. As such, they all appear as a single collection in Wanchain’s NFT bridge. This is the case with XDCNFT, where all collections belong to a single contract.

Conversely, other marketplaces, like OpenZoo, use separate smart contracts for every collection. Because of this, Wanchain’s NFT bridge displays each collection individually, whether it be Zoo Genes, Zoo Boosters, Small Arms Syndicate, CryptoCacs or others.

This quirk will be rectified in a future update.

About Wanchain

We are all connected — Wanchain, the Wide Area Network chain, is the world’s premier decentralised blockchain interoperability solution. Our mission is to drive blockchain adoption through interoperability by building fully decentralised bridges that connect the world’s many siloed blockchain networks. This crosschain infrastructure empowers developers to build truly decentralised crosschain applications to power the future of Web3.