In the previous article “The Isomorphic Binding and Security of RGB++,” we delved into how RGB++ cleverly binds Bitcoin's UTXO with CKB's Cell. This innovative isomorphic binding technology not only simplifies user verification operations but also maintains a high level of security. At the same time, we briefly mentioned RGB++'s Leap operation, which opens up broader application scenarios for users and paves new ways for cross-chain interoperability.
Today, let us explore the Leap function of RGB++ in depth, understanding its basic principles and unique advantages.
Basic Principles of Leap#
In a previous article, we used land, paper deeds, and electronic deeds as examples to introduce the basic principles and operation process of RGB++ isomorphic binding technology. Through that example, it is not difficult to find that the ownership of RGB++ assets (the "land" in the example) is closely tied to Bitcoin's UTXO (the "paper deed" in the example). Whoever can transfer or spend this UTXO (the "paper deed") can unlock the corresponding RGB++ asset (the "land"), because the unlocking conditions set by the Cell containing the RGB++ asset (the "electronic deed" in the example) are that the UTXO on Bitcoin (the "paper deed") has been transferred (i.e., only when the "paper deed" changes, will the "electronic deed" change).
If we construct an RGB++ transaction on the Bitcoin blockchain and set its unlocking condition not to Bitcoin's UTXO but to UTXO from another chain, this asset is equivalent to being cross-chain to another chain, because the next time this asset is spent, it needs to be unlocked by UTXO from the other chain. This is the core principle of Leap's bridge-less cross-chain, which essentially involves "re-binding" the UTXO bound to RGB++ assets. For example, if the asset was previously bound to Bitcoin's UTXO, it can now be re-bound to UTXO on other chains like CKB, Cardano, or Fuel, thus transferring the asset control from a BTC account to a Cardano account.
Currently, RGB++ has achieved bidirectional Leap between the Bitcoin blockchain and the CKB blockchain. It is reported that the RGB++ team is actively promoting the expansion of isomorphic binding and Leap functions to other UTXO blockchains. In the future, RGB++ assets will be able to move freely between these blockchains, achieving truly seamless cross-chain transfers.
For users, RGB++ asset Leap operations can currently be executed through the JoyID wallet and the asset manager Mobit.
Advantages of Leap's Bridge-less Cross-chain#
Cross-chain allows crypto assets to flow freely between different blockchains, and it has become a necessity in a multi-chain world. However, the blockchain world has long suffered from cross-chain bridges. On one hand, mainstream cross-chain bridges on the market often use multi-signature methods, which require high trust assumptions, trusting that the multi-signature parties of the cross-chain bridge will not act maliciously or engage in self-dealing. On the other hand, cross-chain solutions with relatively weak trust assumptions have not been widely adopted due to poor user experience (for example, state proof bridges can be very slow) or high implementation difficulty. Furthermore, in the dark forest of the blockchain world, cross-chain bridges have always been prime targets for hackers, and every incident involving a cross-chain bridge results in substantial losses.
In contrast, RGB++'s Leap cross-chain technology has created an entirely new paradigm: it completely abandons traditional multi-signature cross-chain bridges, achieving truly permissionless, trustless, secure, and efficient cross-chain transfers.
1. Truly Permissionless#
Suppose Alice issues a Meme coin on the Bitcoin blockchain. She approaches the project or operator of a multi-signature cross-chain bridge to support its cross-chain transfer to L2, but she is likely to be rejected. Traditional multi-signature cross-chain bridges typically only support staking of a few top assets and generating corresponding wrapped assets, and they do not support assets with low trading volumes or lesser-known assets because deploying contracts, setting up multi-signatures, monitoring changes in multi-signature addresses, and generating wrapped assets require significant human and material resources.
However, the Leap function of RGB++ is completely decentralized and permissionless. Any asset issued on the Bitcoin chain through the RGB++ protocol can freely Leap between supported blockchains without any third-party authorization or support. Therefore, if Alice issues a Meme coin on the Bitcoin blockchain through the RGB++ protocol, she can Leap this Meme coin to the CKB blockchain at any time and can also Leap back freely. This openness will provide unprecedented opportunities for innovative projects and niche assets.
2. Trust Assumptions#
Even if the project or operator of the multi-signature cross-chain bridge agrees to Alice's request and supports her issued Meme coin, trust assumptions still exist. In traditional multi-signature cross-chain bridges, users lock or stake their crypto assets in a multi-signature address, and they must trust that the operators of the cross-chain bridge will not act maliciously, engage in self-dealing, or run away, because once the assets enter the multi-signature address, users lose direct control over their assets.
RGB++'s Leap technology completely eliminates this trust layer because there are no intermediaries or custodians involved in the process; the assets are always under the user's complete control, requiring no trust assumptions.
3. Security#
Multi-signature cross-chain bridges have always been prime targets for hackers because everyone's assets are locked in a single multi-signature address. If an attack is successful, a large amount of wealth can be stolen, which is why every incident involving a cross-chain bridge results in millions, tens of millions, or even hundreds of millions of dollars in losses. Therefore, Alice and her users need to pray every day that the cross-chain bridge will not fail; otherwise, her issued Meme coin may be stolen by hackers or become worthless.
RGB++'s Leap adopts a peer-to-peer cross-chain model, completely avoiding the risks of centralized asset storage. Each cross-chain transaction is independent, and the assets are always controlled by the user's private key, fundamentally enhancing security.
4. Efficiency#
The Leap bridge-less cross-chain of the RGB++ protocol requires waiting for several additional blocks to confirm in order to avoid block reorganization (the specific time depends on block generation speed and network congestion, especially on the Bitcoin network). For users, since cross-chain operations are not very frequent, this time, although slower than multi-signature cross-chain bridges, is within an acceptable range, especially considering the advantages of Leap cross-chain being more secure and requiring no trust assumptions.
Conclusion#
RGB++'s Leap technology not only addresses the trust and security issues faced by traditional cross-chain bridges but, more importantly, creates a new cross-chain paradigm. As more UTXO chains join the RGB++ ecosystem in the future, the value of this bridge-less cross-chain technology will be further amplified. It not only facilitates the flow of value between different blockchains but also has the potential to promote the entire blockchain ecosystem towards a more open, secure, and efficient direction.
We believe that in a future with multiple chains coexisting, RGB++'s Leap technology will play an increasingly important role.