jakiro
Author: Hao Tian
How to understand @atomicalsxyz’s latest release of AVM virtual machine white paper?Simply put: it is a kind of ability to carry a smart contract system by simulating a Bitcoin virtual machine, allowing the original “stateless” Bitcoin main network to realize the ability to carry a smart contract system, and thus complete the status recording and processing capabilities of more complex assets outside of BTC assets.Similar to Turing complete smart contract.Next, share my understanding:
1) Bitcoin was originally designed as a point-to-point electronic cash system, with certain Script script data storage capabilities, and at the same time, it has some basic OP Codes opcodes, as well as a set of verification asset logic based on UTXO time locks and spending conditions.
Therefore, the Bitcoin network can realize asset management in “stateless” when recording and transmitting BTC assets.Due to the limitations of UTXO minimalist model and predefined state conversion rules, this stateless model can only handle the limited management of BTC single assets.
If you try to add new assets on the Bitcoin network, such as BRC20, ARC20, Runes and other assets, you need to have a more complex dynamic “state machine” model to record the storage, transactions, state changes of these assets.How to achieve it?
In one way, using external protocols and layer2 layer 2 solutions to build a “state machine” model off-chain to extend processing. Currently excellent layer 2 expansion solutions such as @NervosNetwork @RoochNetwork, and even Native solutions such as RGB and Lightning Network areBelongs to this category;
Another way is to directly expand the functionality of Script scripts to add new operations or storage space to handle the creation and transfer of complex assets. Solutions such as Covenant and OP_CAT that rely on BIP proposal standards are passed belong to this;
The above two methods are either too “active” and it is difficult to reach consensus and unification in a short period of time, or too “passive”, with great uncertainty.AVM virtual machines give a special processing solution in between and to directly build a virtual machine execution environment on the Bitcoin main network.
2) How to do it?The main working principle of AVM includes three parts:
1. Bitcoin script simulation is actually a Bitcoin instruction set, and Turing complete properties are achieved through dual-stack PDA (pressible into storage automatons);
2. Sandbox operating environment, the entire simulator is in a controlled isolated environment, so that the execution in the sandbox and the execution outside the execution do not interfere with each other;
3. State hashing allows participants to verify whether the status of their indexer is correctly synchronized, preventing potential aggression from inconsistent states.
Simple understanding: AVM directly utilizes the current limited storage space of BTC and OP Codes processing framework, and introduces a special encoding and decoding method (sandbox environment) into each BTC main network transaction.
This sandbox comes with an indexer, a sandbox parser (instruction set), global Database (database), etc., which can independently complete the management of a complete set of asset storage, transaction status records, etc., which is equivalent to a built-in dynamic on the BTC main networkThe “state machine” can then realize complex smart contract processing, state synchronization and verification.
3) With the AVM virtual machine, theoretically, the Bitcoin main network can have basic smart contract operation functions, allowing Bitcoin to manage multiple complex assets and implement complex state logic DApps, which is equivalent to giving the Bitcoin network a certain amount ofSelf-built ecological functions.
This is of course a great progress, at least as BTC expansion capabilities innovation as RGB, Lightning Network and various excellent layer two protocol processing solutions.Even in terms of Native, it is better than other solutions.
However, AVM relies on Bitcoin Script scripts for encoding storage and OP Codes for transaction execution, so it is generally limited by the main network performance of BTC, such as: block storage space size, output speed, etc.
Just imagine, a DeFi project built on AVM can only process 7 transactions per minute, and it takes ten minutes to wait between two state conversions. Such a smart contract is still bound even if it is theoretically complete.Moreover, relying on Bitcoin Script script instruction sets to develop complex contract functions is more complex and difficult than developing smart contracts in languages such as Ethereum Solidity.
Moreover, AVM’s white paper only clarifies a built-in virtual machine execution method of Make Sense. The problems such as how its actual deployment and application environment runs online are still unknown.
above
Overall, I tend to regard the development and implementation of AVM as a beneficial and active exploration based on BTC main network Script script expansion, which can indeed drive some simpler smart contracts to be implemented on the BTC main network, and at the same time, the Bitcoin main network canPlay a greater proportion and value in the construction of the second-tier ecosystem and BitVM on-chain and off-chain combination ecosystems.
However, like other BTC expansion solutions, AVM also has its advantages and disadvantages. It also needs to rely on the ecological construction after implementation to expand its “orthodox” appeal. It is recommended to maintain a rational, cautious and optimistic attitude.
