ZETINA

The Zetina is a shared peer-to-peer network of Zero-Knowledge Provers. This network allows any party to join and utilize its services, operating with two main user roles:

  1. Delegators: Users who present jobs to be executed on the network.
  2. Executors: Users who execute the jobs submitted by Delegators.

Key Components

Peer-to-Peer Network of Hosts

This component ensures effective event-driven communication among hosts, facilitating the distribution of tasks and information across the network. Hosts stay updated and informed about new jobs through this network.

Registry Contract

This component manages the rewarding process for Executors. It verifies and awards Executors for correctly executing jobs and provides a secure platform for Delegators to deposit funds, which are then used to reward Executors.

Workflow Overview

  1. Delegator Initiates Job:

    • The Delegator defines a job, consisting of a Job Header and a Job Body, and stores the Job Body in a Distributed Hash Table (DHT) within the p2p network. The Job Header is then sent using a Gossip-Sub message.

  2. Executor Receives Job:

    • An Executor receives and verifies the Job Header. If valid, they retrieve the Job Body from the DHT, check the Delegator’s account solvency, and execute the job.

  3. Job Execution:

    • The Executor executes the job, producing a Job Witness containing the results and a zero-knowledge proof of correct execution.

  4. Submission and Reward:

    • The Executor submits the Job Witness to the Registry. Upon verification of the Delegator’s signature, the Registry sends the reward to the Executor.

Architecture and Workflow

We will explore the job pathway as it goes from Delegator to Executor via the peer-to-peer network to better understand the workings of this service:

  1. Delegator Initiates Job: The Delegator, who has funds deposited into the Registry and is part of the Zetina network, initiates a job. They define the job, which consists of a Job Header and a Job Body. The Job Header contains basic information about the task, such as its reward and its hash, while the Job Body contains the Cairo program to be executed.

  2. Storage in Peer-to-Peer Network: The Delegator signs and stores the Job Body in a Distributed Hash Table (DHT) within the peer-to-peer network. Simultaneously, they sign the Job Header and send it to the peer-to-peer network using a gossip-sub message.

  3. Executor’s Perspective: An Executor within the network receives the Job Header from the Delegator. The Executor first verifies the validity of the message by checking if the Job Header was correctly signed by the Delegator. If valid, the Executor retrieves the Job Body from the DHT and performs similar checks.

  4. Account Solvency Check: The Executor also checks if the Delegator’s account has a safe amount of funds remaining for the job reward. If everything checks out, the Executor proceeds to execute the job.

  5. Job Execution: The execution process consumes time and resources on the host machine. Once completed, the Executor produces a Job Witness containing the results of the Cairo program and proof of its correct execution.

  6. Submission to Registry and Receiving Reward: The Executor promptly submits the job to the Registry. The Registry verifies the signature of the Delegator, the hash of the job, and the job proof of correctness. If all criteria are met, the Registry sends the funds as a reward. The Delegator subscribes to the Registry contract events and, when a job is successfully registered, the output of the job is emitted.

To sum up, the Delegator pays the Executor for doing their job in a way that is safe and sound for both parties of the Zetina network.

Architecture

Details on Delegator Working Process

  1. The Delegator comes up with the Cairo Program and creates the Job Header and Job Body, sending them to the peer-to-peer network.
  2. If they have enough funds in the Registry and they place an attractive offer, the task will be picked up.
  3. After broadcasting the Job Header, they listen for the events from the Registry to receive the verified Job Witness they pay for.

Details on Executor Working Process

  1. Job Record: This is a crucial component for the Executor. It provides information about available jobs. The Executor’s goal is to identify the most profitable job opportunities from the Job Record. Since multiple Executors might start the same job simultaneously, there’s a competition aspect involved. The first Executor to submit a job gets the reward for completing it.

  2. Job Header: Once the Executor selects a job from the Job Record, they obtain the Job Header. This contains essential metadata about the job. It acts as a pointer to the actual task details, which are stored off-chain in the peer-to-peer network.

  3. Job Body: The Job Body comprises all the necessary information required for executing the task, including the Cairo program and public inputs. This information is fetched from the peer-to-peer network. The Executor transforms the Job Body into the Job Witness by executing the task locally.

  4. Job Witness: This is the output generated by executing the task locally. It serves as proof of correct execution of the program. The Executor’s main objective is to submit this Job Witness to the StarkNet Registry promptly, so they can claim the reward for completing the job before another Executor does. It’s a race against time to submit the Job Witness and secure the reward.

Registry Contract

The Registry contract is a critical component of the Zetina network, responsible for the following tasks:

  1. Fund Management: Delegators deposit funds into the Registry to offer rewards for job execution. The Registry securely holds these funds until they are distributed to Executors.

  2. Verification and Reward Distribution: The Registry verifies the submitted Job Witnesses from Executors. This involves checking the Delegator’s signature, the job’s hash, and the proof of correct execution. If the job is verified successfully, the Registry distributes the corresponding reward to the Executor.

  3. Event Emission: The Registry emits events upon successful job verification and reward distribution. Delegators can subscribe to these events to receive notifications about the status of their jobs.

  4. Security: The Registry ensures that only valid and correctly executed jobs are rewarded. This provides a layer of trust and security for both Delegators and Executors in the network.

By managing the financial and verification aspects, the Registry contract plays a pivotal role in maintaining the integrity and efficiency of the Zetina network.

Installation

Contributors