B² joins hands with Babylon: Complete the combination of modular DA and secure staking returns

Source: View on the Chain

What do you think of the latest cooperation between @BSquaredNetwork and @babylon_chain? One is a BTC modular expansion solution provider that launched the B² Hub modular DA layer, and the other is a BTC second-layer POS security pledge service provider that brings native asset pledge interest generation into the BTC network.

The combination of the two is similar to the combination of Celestia modular DA layer + Eigenlayer shared security layer? Next, let me analyze the technical implementation process:

According to the announcement, both the B² Hub and B² Rollup layers of this cooperation will use Babylon's BTC pledge to enhance security and support BTC LSD and BTC Restaking functionality.  

Why can BTC staking provide security for B² internal components? Take B² Hub as an example for further explanation:

1) B² Hub is a key component in the DA layer of B² Network. It is equivalent to a decentralized verification network that will handle Sequencer screening, distributed Storage storage, Prove processing of data and proofs from the ZK-Rollup layer, Indexer maintenance after generating Commitments and sending inscriptions to the BTC main network, and verification of the results of Commitment challenges for challengers, etc.

It should be said that every key step in B² Hub involves the verification and governance of a decentralized Validators network.

The question is, how to ensure the security of this verification network?

One ​​idea is to use Validators to perform POS pledge on the local network, and perform rewards and slashes according to the agreed specifications. The pledged assets are the tokens of the local second-tier chain. This solution is theoretically It is feasible, but lacks a higher level of security; another idea is to let these Validators directly participate in the asset pledge of the BTC main network, and then use them to ensure the security of external POS systems.

Obviously, when B² Hub cooperates with Babylon, it will advance to the second security solution, which will enhance the security of its decentralized verification network.

2) How does the BTC pledge system introduced by Babylon ensure the security of the external POS system?

1. Time lock, Babylon will lock the assets requested to be pledged by the main network for a certain period of time. During the locking period, the pledger cannot use the pledged assets, and will also become a pledger. The constraints on the POS external system require pledgers to follow the rules of the external POS system. Once a violation occurs, the pledged assets may not be redeemable;

2. One-time Signature EOTS, Babylon introduces a signature scheme where if the same private key is used to sign two different blocks at the same block height, the private key is exposed. This means that if a staker attempts to double-spend, his private key will be leaked and his staked BTC assets will be forfeited by Slash. EOTS signature can be realized through BTC’s native Schnorr signature, and multi-signature governance equivalent to BTC’s security level will take effect;

3. In the final round of multi-signature consensus, Babylon stipulates a zone A block will only be finalized when it receives EOTS signatures from more than 2/3 of the BTC stakers, which means that when a malicious node wants to double-sign with less than 1/3 of the signatures, its private key will be exposed and the pledged assets will be exposed. will be Slashed. This mechanism further ensures that pledge nodes can participate in POS system governance in accordance with regulations.

3) So, how does Babylon provide security support for B² Hub? Specifically:

First of all, B² Hub’s decentralized verification network needs to reach a consensus mechanism, including nodes pledging BTC and B² tokens to participate in governance, and adopting a dual asset pledge mechanism. It can avoid some nodes in the second-layer network from trying to control the network by purchasing large amounts of B² tokens, because it must have a large amount of BTC assets pledged on the main network at the same time.

Secondly, B² Hub has set up Epoch consensus and CheckPoint. During each Epoch, the verification node needs to conduct governance votes on all on-chain actions, and each POS second-layer chain block has It is finally determined that you need to wait for at least two BTC mainnet block timestamps. This will give enough time for the second layer's own governance mechanism to determine the certainty of state transfer to punish possible evil behaviors;

Finally, Babylon cleverly uses BTC timestamps to prevent "Long range attack". To put it simply, if a node in the POS chain attempts to create a fork on the second layer and builds a longer forked chain, if the new forked chain is longer than the original chain, it will cause damage to the consensus of the entire second-layer network.

It will take a long time for malicious nodes to achieve their goals. If the POS chain blocks can be linked to the Bitcoin mainnet block timestamp, every Each POS block corresponds to a Bitcoin block, wouldn’t the problem be solved?

Just imagine, if a malicious node in the POS chain attempts to carry out a long-range attack, it not only needs to obtain the longest chain of consecutive blocks on the POS chain, but also needs to achieve the longest chain on the BTC network. For long-chain control, the cost of controlling the POS chain may be lower, but to control the BTC mainnet chain at this stage, the computing power cost is estimated to be astronomical.

Of course, in addition to enhancing security, B² Hub and Babylon are also of great benefit to the ecological interoperability of both parties. They can bring direct re-pledge income. Users pledge BTC to B² Hub. Validator can get token rewards provided by B². When the Babylon staking mainnet is online, you can also enjoy the re-staking income of the Babylon ecosystem. You can get stBTC by staking BTC, and you can also get the staking contracts in the B² Hub staking contract and the Babylong staking contract. Double benefit.

Above

The modular DA provided by Celestia has become a more cost-effective choice for Ethereum Rollup layer 2, the long-term positioning of B² Hub It also serves as a modular DA layer to provide services for the multiple Rollup layer2 chains of the BTC ecosystem.

B² Hub’s original off-chain zk-Rollup proof system and BitVM-style Commitment mainnet challenge are equivalent to realizing a POS off-chain consensus that is close to the BTC mainnet security consensus. After all, there is a challenger mechanism, and node behavior will most likely be considered "optimistic".

Eigenlayer's re-pledge guarantees the EigenDA node service provided by the gain Buff given to Ethereum nodes, which is equivalent to enhancing the node verification capabilities through an economic incentive mechanism. By analogy, the role of Babylon is actually very similar to the Function provided by Eigenlayer.

In short, if the impact of this cooperation between B² Network and Babylon on the BTC layer2 ecosystem is compared to the effect of Celestia DA and Eigenlayer Restaking on Ethereum layer2, would it be easier to understand? Already?