Aleo: A Privacy-Protection Blockchain Based on zk-SNARKs

Aleo is a blockchain project dedicated to privacy protection, achieving higher privacy and scalability through zk-SNARKs technology. The core idea of the project is to enable users to authenticate their identity and process data while protecting personal information.

Project Overview

Privacy Protection

The core technology of Aleo is zk-SNARKs ( ZKPs ), enabling transactions and the execution of smart contracts to be conducted with privacy protection. By default, transaction details such as the sender and amount are hidden. This design not only protects user privacy but also allows for selective disclosure when necessary, making it very suitable for the development of DeFi applications.

Main components include:

1. Leo programming language: A language specifically designed for developing zk-SNARKs applications (ZKApps), reducing the requirements for developers' knowledge of cryptography.

2. snarkVM and snarkOS: snarkVM allows off-chain execution of computations, with only the results being verified on-chain, thus improving efficiency. snarkOS ensures the security of data and computations, and supports permissionless functionality execution.

3. zkCloud: Provides a secure and private off-chain computing environment that supports programming interactions between users, organizations, and DAOs.

Aleo also provides an integrated development environment (IDE) and software development kit (SDK), supporting developers to quickly write and publish applications. Developers can deploy applications in Aleo's program registry without relying on third parties, thereby reducing platform risks.

Scalability

Aleo adopts an off-chain processing method, where transactions are first computed on the user's device to generate proofs, and then only the verification results are uploaded to the Blockchain. This approach greatly improves transaction processing speed and system scalability, avoiding issues of network congestion and high costs.

Consensus Mechanism

Aleo has introduced AleoBFT, a consensus mechanism with a hybrid architecture that combines the immediate finality of validators with the computational power of provers. AleoBFT not only improves the level of decentralization of the network but also enhances performance and security.

Main Features:

1. Block rapid finality: Ensure that each block is immediately confirmed after generation, improving node stability and user experience.

2. Decentralized Assurance: Separating block production from coinbase generation, validators are responsible for generating blocks, while provers conduct proof calculations, preventing a few entities from monopolizing the network.

3. Incentive mechanism: Validators and provers share block rewards; encouraging provers to become validators by staking tokens, thereby enhancing the network's level of decentralization and computing power.

Aleo allows developers to create applications that are not restricted by gas limits, making it particularly suitable for applications that require long-running processes, such as machine learning.

Latest Developments

Aleo will launch its incentive testnet on July 1st, here is some important information:

1. The ARC-100 proposal has been passed, involving compliance and security measures.

2. The validator incentive program will start on July 1 and run until July 15, distributing 1 million Aleo points as rewards.

3. The initial supply is 1.5 billion tokens, with an initial circulating supply of approximately 10%.

4. The Testnet Beta will undergo its final network reset, adding ARC-41 and new puzzle features.

5. Code freeze has been completed.

6. Validator Node Expansion Plan: Initially 15 nodes, with a target to increase to 50 within the year, and ultimately reach 500. To become a delegator requires 10,000 tokens, while to become a validator requires 10 million tokens; these amounts will gradually decrease.

Synthesis Puzzle Algorithm Analysis

Aleo has recently updated the puzzle algorithm, focusing not on the generation of zk proof results, but rather on generating the intermediate data witness before the proof generation. The new algorithm is called Synthesis Puzzle, and its core is to generate a common EpochProgram for each epoch, constructing R1CS proof circuits to produce the corresponding R1CS assignment (, which is the witness ), and serves as the leaf node of the Merkle tree, calculating the Merkle root and converting it into the solution's proof_target.

Main process:

1. Each puzzle calculation is called a nonce, constructed from the address receiving the mining reward, epoch_hash, and the random number counter.

2. In each epoch, all provers calculate the same EpochProgram, with random numbers generated from the instruction set sampled by the epoch_hash.

3. Use nonce as a random seed to generate the input for EpochProgram.

4. Aggregate the R1CS and input corresponding to the EpochProgram to perform witness calculation.

5. Convert the witness into a sequence of Merkle tree leaf nodes.

6. Calculate the Merkle root and convert it to the solution's proof_target, checking whether it meets the current epoch's latest_proof_target.

7. Multiple solution calculations can be performed by iteratively updating the EpochProgram input through the counter within the same epoch.

This update changes the puzzle from generating proof to generating witness. The solution calculation logic is consistent within each epoch, but the calculation logic differs significantly between epochs. The new algorithm abandons the previous MSM and NTT calculations, posing challenges for GPU optimization. Due to the serial dependencies in the witness generation process, achieving parallelization also faces certain difficulties.