BRC-721E links Ethereum NFTs with Bitcoin Ordinals

Bitcoin Ordinals are a new layer-2 solution that allows for decentralized storage of digital art on the Bitcoin blockchain. With the launch of the BRC-721E standard, Ordinals now allows users to transfer their Ethereum ERC-721-based non-fungible tokens (NFTs) to the Bitcoin blockchain.

The BRC-721E standard was jointly launched by the Ordinals market, an Ordinals-based marketplace, and the Bitcoin Miladys NFT collection. This new standard enables the conversion of immutable and verifiable ERC-721 NFTs to Ordinals. Initially, metadata is not stored on-chain, but users can store a lower-quality preview image and include a reference to the Ether (ETH) burn in the raw image data.

Our #Bitcoin Ordinals bridge is now live In collaboration with @OrdinalsMarket_ & @xverseApp Bridge: New token standard: Marketplace: Let’s take over #Bitcoin !

— Bitcoin Miladys (@BitcoinMiladys) May 29, 2023

The migration process begins by burning the ERC-721 NFT with an ETH call function. The burning of the NFT is an irreversible process and acts as an on-chain inscription method. To claim the ETH burn on Bitcoin, the user must inscribe valid BRC-721E data, after which the bridged NFT will appear on a custom Ordinals market collection page with complete metadata.

The indexers that check the burned NFT data inscriptions ensure that a token has no more than one valid inscription and that the genesis address matches the burn transaction call data.

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The Ordinals market claims that the fundamental principles of BRC-721E and the flexibility of the indexers allow for the protocol to evolve over time, despite the fact that metadata is initially not stored on-chain.

Since its launch in January 2023, Bitcoin Ordinals has received widespread attention from the crypto community. The launch of the BRC-20 token standard in March created an experimental fungible token standard designed specifically for the Bitcoin blockchain. The combination of BRC-20 with Ordinals opened new gates for minting tokens on the Bitcoin blockchain, with the emergence of many popular BRC-20 tokens such as Ordinals (ORDI), Vmpx (VMPX), and Pepecoin (PEPE).

The number of BRC-20 tokens has skyrocketed from a few hundred in its first week to over 25,000 at the time of publication. However, the rise of Ordinals and the new token minting era has not been unanimously well-received, with many Bitcoin (BTC) proponents criticizing the new method as inefficient and wasteful.

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