On May 20, 2024, the Bitcoin Layer2 development team BEVM released the technical yellow paper titled “Taproot Consensus: Title: ‘Taproot Consensus: A Decentralized BTC Layer2 Solution.’ This paper outlines the Taproot Consensus, which is constructed and based entirely on native Bitcoin technologies such as Schnorr signatures, MAST, and Bitcoin SPV nodes.
Taproot Consensus is an advancement in native Bitcoin scalability. Unlike the Bloomberg Consensus, Taproot comprises various advanced technologies of the Bitcoin without tweaking the primary codes of the Bitcoin.
History of Bitcoin’s Technical Iterations
October 31, 2008: Satoshi Nakamoto introduced the world to Bitcoin as a peer-to-peer electronic cash system through the paper “Bitcoin: A Peer-to-Peer Electronic Cash System,” also establishing the basis for SPV—Simple Payment Verification.
January 3, 2009: Nakamoto produced the first block of Bitcoin, the Genesis Block, through mining. The initial implementation of the code was employed with the usage of a certain type of digital signature called Electronic signature based on the elliptic curve Diffie–Hellman algorithm instead of using Schnorr signatures that are more appropriate to be used here since they were patented during that time.
Schnorr is capable of maintaining all the characteristics and security postulations inherent in the functionalities of the ECDSA, can come with the characteristics of ECDSA beyond the 15-signature limits, and can spearhead the Bitcoin with the results of approximately a thousand addresses without negatively interfering with the signing process.
2018: It was the core developers of Bitcoin that incorporated Schnorr signatures into the peer-to-peer network.
November 14, 2021: The Taproot upgrade incorporated Schnorr signatures to make it easy to create complex contract-like structures and included MAST for addressing abstract syntax trees to support multi-sig decentralized management.
Following these advancements, the BEVM’s Taproot Consensus solution also adopts Schnorr signatures with MAST, extending features to multi-signature addresses and offering more extensive possibilities of business processes in the Bitcoin Layer2.
Overview of the Taproot Consensus Solution
The yellow paper introduces some of the challenges associated with Bitcoin, including the fact that it is non-Turing complete and, therefore, lacks sophisticated functionalities for smart contracts. It advocates that work should focus on extending Bitcoin’s current capacities and constructing it as a Layer2 application instead of reconstructing Layer1.
Taproot Consensus is created by integrating Bitcoin’s Taproot technology (Schnorr signatures and MAST), off-chain SPV light nodes of Bitcoin, and BFT PoS consensus model to develop a consistent Layer2 BEVM ecosystem.
Detailed Explanation of Taproot Consensus Architecture
The Taproot Consensus framework is built upon three innovative components: Schnorr+MAST, Bitcoin SPV, and Aura+Grandpa.
Schnorr+MAST: The Taproot Consensus architecture leverages Schnorr signatures and the Abstract Merkle tree syntax tree introduced under the Taproot Bitcoin upgrade. This combination makes it possible to decentralize Bitcoin management through the code’s use of multi-signatures.
Bitcoin SPV: The BEVM system consists of the Bitcoin UTXO Set Merkle Tree, which enables the validator nodes to serve as Bitcoin SPV (Simplified Payment Verification) Light nodes so they can sync permissionlessly and securely the state of the Bitcoin network without running a full node.
Aura + Grandpa: The Taproot Consensus framework utilizes Aura and Grandpa’s advanced PoS (Proof-of-Stake) consensus protocols, ensuring high consistency and Byzantine fault tolerance among the network nodes.
In the academic field and literature, many terms describe signals and their power in the market, especially when collected together in one aggregate signature.
In the BEVM system, several validators hold a Schnorr signing key for BTC. Schnorr’s witnessing capability allows for efficient signature aggregation in the system, making it more secure and efficient. The virtual aggregation of the public key formed through the Musig2 multi-signature scheme forms a large MAST tree that permits BTC flow and inscription to the threshold signature address.
Completing MAST trees and validating the inscriptions, Bitcoin transfers of the MAST threshold signature address enable the submission of BTC data from Bitcoin’s mainnet on BEVM. This approach creates a secure and permissionless environment for interacting with the two blockchain systems.
Other Technical Details in the Yellow Paper – True Decentralization
The yellow paper covers the technical details extensively, including Schnorr signatures, MAST, Bitcoin SPV light nodes, and the Aura+Grandpa consensus schemes. This piece will be highly informative for those keen to learn more about the exact technologies applied to Bitcoin solutions.
The paper also looks at the elements of Musig2 and compares it with other BTC Layer 2 projects that it offers, like Mezo, which uses BTC. While the tBTC solution is connected to the network of 9 signatories, Taproot Consensus is fully incorporated into multi-signature networks and implemented with BFT PoS consensus, where Byzantine Fault Tolerance is achieved to organize genuine decentralization.
The major difference can be described based on how decentralization is being implemented. For distributed networks emphasizing distribution, we observe that many are not Byzantine fault-tolerant for reaching consensus. While blockchains, as distributed structures, leverage Byzantine fault-tolerant consensus, it would be quite true that they are highly decentralized. Taproot Consensus adopts this more elaborate structure to integrate Schnorr signatures, MAST, Bitcoin SPV lightweight nodes, Aura, and Grandpa consensus types to form cohesive and highly secure decentralized layer-2 scalability.
This integrated approach improves the scalability and flexibility of the Bitcoin network and increases the security and stability of the BEVM network. By incorporating advanced cryptographic mechanisms and master nodes, Taproot Consensus establishes itself as a new generation of decentralized Layer 2 solutions based on Bitcoin.
Conclusion
In a technical yellow paper, the team behind the BEVM gives all the details required to understand Taproot Consensus, a Bitcoin Layer2 scalable solution fully developed considering the native Bitcoin assets.
It is technologically coherent and aligns with Bitcoin’s original technological path; it is a real continuation of the improvement of native Bitcoin scalability. The following are some reasons why solutions such as Taproot Consensus will still be necessary in the developing ecosystem of Bitcoin. We will see these as major cornerstones to true decentralized Bitcoin Layer2 solutions.
