Learn the details of how Aleo . works

• Aleo - Layer 1 blockchain platform based on Zero-Knowledge Proofs technology
• How Aleo . Works
• Computer environment: zkCloud
• Programming language: Leo
• Consensus Algorithm: AleoBFT
• Ending

Aleo is a Layer 1 blockchain that uses Zero-Knowledge Proofs technology to allow developers to build private applications on top of this network. Developers see blockchains using Zero-Knowledge Proofs as the third wave. First there was Bitcoin, then there was Ethereum and now there is Aleo.  

In the previous article, we have had an overview of the Aleo project , in this article, we will learn together in detail how Aleo works.

Aleo – Layer 1 blockchain platform based on Zero-Knowledge Proofs technology

As we all know, Aleo is a typical privacy public blockchain using Zero-Knowledge Proofs technology – this is a type of cryptographic protocol that allows one party (Provenor) to prove to another party (Verifier) ​​that they know a certain piece of information without disclosing any information about the actual content of that information. 

ZKP is a way to prove that you know something, own something, or have done something without disclosing any information about it. As people are being engulfed by the remnants of the FTX exchange's liquidity crisis, Zero-Knowledge Proofs is a bright spot. This is a useful tool, specifically designed to help avoid the kind of fraud that FTX causes. 

For blockchains specifically, ZKP has two useful uses: scalability and privacy.

Taken together, ZKP allows blockchains to approach the performance of centralized services and exceed their security and privacy capabilities, while maintaining the benefits of decentralization.

Aleo was originally conceived as an L2 on Ethereum, but ZKP on Ethereum is larger – they have to use the entire state of the application, and Ethereum does not support SNARK-friendly primitives (hash functions and elliptic curves. So Aleo team rewrote the plan and decided to build their own L1 to provide cheaper ZKP. 

Aleo is taking the most radical approach to building a blockchain based on ZKP from the ground up. Instead of building an EVM-compatible chain so developers could build apps using the familiar Solidity programming language, it created its own virtual machine, snarkVM, and the Leo programming language. Instead of relying on existing consensus mechanisms like Proof of Work (PoW) or Proof of Stake (PoS), it uses a combination of the two, with a useful tweak on PoW called Proof of Succinct Work. As a result, ZKPs on Aleo are much cheaper than on Ethereum.

Aleo is a decentralized platform that uses its blockchain to verify and store proofs, which are efficient Zexe transactions. It uses a Bitcoin-like architecture, with a ledger and a record, or a UTXO (unused transaction output) model, where the input specifies the address where the asset came from and the output specifies the address. only to which the content is sent, with a value representing the amount of assets sent. Aleo's consensus algorithm is the same as Proof of Work, with a few key differences. That's largely where the comparisons end and where a host of new content created by Aleo emerges. 

How Aleo . Works

How Aleo works will revolve around three main parts:

• Computing Environment and Blockchain: zkCloud
• Programming language: Leo
• Consensus Algorithm: AleoBFT

Computer environment: zkCloud

A typical programmable blockchain, like Ethereum, works by executing programs on a chain of virtual machines that must be run by every node in the network. If you have heard of “EVM” or “EVM compatible”, that is the virtual machine of Ethereum. 

One of Aleo's biggest differentiators is that zkCloud splits it into two parts: snarkVM is a virtual machine that runs applications off-chain and sends protected transactions to the Aleo blockchain, snarkOS. In cryptographic terms, it separates execution (snarkVM) from state (snarkOS).

There is an important difference between Zexe and Aleo is that Zexe allows both data privacy and functional privacy, whereas Aleo has data privacy but no functional privacy. 

On Aleo, you can't see the input and output of the program or the sender and recipient of the credit, but you can see which program has been interacted with. While the Aleo team devised a way to ensure functional privacy from the start, the team felt that focusing on data privacy was the right trade-off for Aleo for the sake of removing privacy. of functionality that improves performance while benefiting developers with tools to protect privacy.  

In his blog post, Alex likened the relationship between snarkVM and snarkOS to “shadow objects: When you see a shadow, you know that something created the shadow, but very It's hard to figure out the details or pinpoint what it is." 

Programs running off-chain in snarkVM can run for any length of time. If you want, you can run a program that calculates from pi to trillions of digits over the course of many months as long as eventually a protected transaction is sent to snarkOS. 

In addition, this architecture provides a few more key benefits: 

• Privacy : Since only the proof is online, anyone without a quantum computer will not be able to view the transaction details. 
• Higher Throughput : Nodes only verify proofs instead of running programs. 
• Security is maintained : ZKP cryptographically guarantees that the program runs correctly, removing existing reliability assumptions with the cryptoeconomic guarantees of other L1s and L2. 

This architecture allows Aleo to come close to breaking the impossible trinity of scalability – it allows Aleo to be decentralized, scalable, and secure – with added privacy to have The best solution.

Programming language: Leo

Aleo's goal is for casual Web developers to be able to write private applications without having to think about low-level cryptography. The most popular languages ​​in coding, Solidity and Rust, don't work perfectly for ZKP, and these technology-specific languages ​​are all math-based. To use them, the Aleo team explains that “you need to know a lot of advanced math.”

To build a ZKP, you need a proof system (in Aleo's case, SNARK and more specifically MARLIN SNARK) and a ZK circuit. Just as the circuits in your computer have NAND gates that take 0s and 1s as inputs and outputs, ZK circuits use add and multiply gates that take the numbers “0 to p” as inputs and outputs . Creating a ZK circuit means putting all those gates together manually.

Aleo surveyed the landscape of domain-specific languages ​​(DSLs) and came across ZoKrates. Aleo changed the syntax and developed it to create his own programming language called Leo.

Leo is built to look and feel more like JavaScript, the world's most popular programming language, than Assembly. If ZKP penetrates the fabric of the Internet, it becomes extremely easy for developers who are not familiar with ZK to incorporate ZKP.

Basically, this language is very complex, abstracting circuit programming and other low-level concepts. Therefore, it is easier for developers to build private applications.

It receives the code as shown below:

Aleo takes the code and presents proof that you ran your computation correctly, this proof can be sent from snarkVM to snarkOS for verification by nodes. 

In addition to this language, Aleo also develops a range of other tools to make it easier for developers, including a testing framework and a package manager. They wrap it all up in Aleo Studio – the first IDE (integrated developer environment) for Zero-Knowledge Proofs.”  

Consensus Algorithm: AleoBFT

AleoBFT combines Proof of Stake (PoS) and a type of Proof of Work (PoW) – specifically called Proof of Succinct Work (which itself is a subset of Proof of Necessary Work).  

We will go into the details of this section in another post. Basically AleoBFT is designed to do three things: secure the protocol, ensure that there are enough experienced validators to serve the application's zkSNARK needs, more incentive, prove efficient and cheap than. 

Ending

Above is how Aleo works – a Layer 1 blockchain project using ZKP. Among public blockchains, ZKP mining can be accepted by any L2 of the ZK chain, but L1 is currently only allowed by Aleo. In contrast, Aleo does not require parallel computation, so idle GPU miners can be docked seamlessly. In the following article, we will continue to dig deeper into AleoBFT.