The Oracle Problem

Blockchain empowered smart contracts are isolated from the internet world and cannot access external data directly. Computation within the smart contract is also excessively expensive and limited by resource capacity.


DOS Network - A Decentralized Oracle Service supporting multiple heterogeneous blockchains. DOS Network brings real-world data, event and computation power to smart contract in a secure, reliable, efficient and scalable way.


  • Decentralized and Reliable

    A trustworthy decentralized solution without single point of failure.

  • Secure and Trustworthy

    Driven by Verifiable Random Engine and advanced cryptographic signatures.

  • Real-Time and Verifiable

    Near real-time request fulfillment and on-chain verifiable response.

  • Scalable at a Low Cost

    Data query throughput and computation capacity increase as more nodes join.

  • Compatible to Heterogeneous Blockchains

    Support multiple blockchains and enable cross-chain interactions.

  • Crypto Incentivized

    Dynamic network incentivized by honest participation rewards.

Use Cases

  • Automatic Decentralized Insurance Payout

    With DOS Network, many scenarios like flight delay insurance are able to achieve automatic indemnification by bringing external insured events to the on-chain insurance contract.

  • Stablecoins and Crypto Derivatives

    Stablecoins and crypto derivatives require a frequent usage of DOS Network to fetch realtime price feeds reliably and verifiably.

  • Crypto Lending Platform

    DOS Network makes it easy for crypto lending platform to get token exchange rates, import borrowers' social media data and trustlessly determine the interest rates on the fly.

  • Cross-chain Dex

    Deploying two DEX contracts on different blockchains and DOS Network acts as a bridge to connect heterogeneous transactions crossing chains.

  • Casinos and Games

    Secure randomness is core to blockchain based casinos and games. DOS Network provides unpredictable, verifiable, and secure randomness to drive those applications.

  • Computation Marketplace

    Commercial computation intensive tasks, such as machine learning model training, 3D rendering, benefit a lot from verifiable off-chain computation market.

Strategic Partners

2021 Roadmap

  • Pre-2021

    • Released Mainnet 1.0 on Ethereum Network
    • _
    • Initiated Staking and Node Runner Program
    • _
  • Q1

    • Deploy Oracle Functionality on Binance Smart Chain (BSC)
    • Launch Data Stream Services on Ethereum and BSC Network
    • Substrate-based Oracle Chain Development
  • Q2

    • Deploy on Other EVM-compatible Blockchains with Active Users
    • Incubate and Partner with DeFi Projects to Boost DOS Adoption
    • Release Substrate-based Oracle Chain Alpha Testnet and Wallets
  • Q3 ~ Q4

    • Release Oracle Chain Mainnet and Prepare for Parachain Auction
    • Reseach Optimism Rollup to Introduce DOS to L2 Network
    • DAO Setup for Network Parameters and Decentralized Governance

Frequently Asked Questions

  • What is DOS Network?

    DOS Network is a chain-agnostic layer 2 decentralized oracle network that offers realtime data feeds and verifiable computation power to mainstream blockchains. It connects on-chain smart contracts and Ðapps with off-chain data sources and unlimited computation power, enabling smart contracts with more real world use cases.

  • What problems can DOS Network solve?

    Besides the widely-discussed scalability problem, currently there are another two big issues hindering the widespread adoption of smart contracts and large-scale commercial Ðapps:

    • Blockchain is a closed and deterministic system and the execution of a given smart contract in all validating nodes must reach a unanimous result, otherwise consensus is broken. This is an inherent limitation of blockchain consensus mechanism. Thus, smart contracts are not allowed to perform network I/O operations with off-chain world, they can only consume input from on-chain states and transaction data.
    • There are a lot of on-chain resource limitations such as the expensive storage cost and computation constraint (gas limit, cpu time limit, etc.), preventing complex computing in smart contracts.

    The mission and value of DOS Network is to solve these two problems to enrich smart contracts and decentralized economy with real world data and more computing power, paving the way for the mass adoption of blockchain.

  • What is the architecture of DOS Network?

    The architecture of DOS Network is partitioned into two layers with several key components:

    • On-chain part: A set of system and governance contracts are to be deployed on supported blockchains, mainly including functionalities such as request handling and response/computation result verification, node registration and staking, stats monitoring, payment processing, etc. On-chain system contracts also provide a universal interface to developers and user contracts on all supported chains.
    • Off-chain part: A client software implementing the core protocol running by third party users (a.k.a node operators), constituting a layer 2 distributed network serving oracle requests. Client software includes several important modules: event monitoring and chain adaptor module, distributed randomness engine module, cryptography and off-chain group consensus module, request and/or computation task processing module depending on the type of oracle service the node operator provides.
  • How does DOS Network provide real world data to smart contracts?

    It basically follows the request-response pattern. Through the on-chain SDK we develop, smart contract (developer) specifies the origin and format of the required data by making a message call (oracle request) into system contracts. The request is randomly dispatched to an off-chain worker group, inside which member nodes fetch from the specified data source and cryptographically reach off-chain consensus within the selected group. The proof along with the response data are sent back to the system contracts just in 1 transaction, triggering on-chain verification.

    Unlike prediction market, DOS Network is able to connect any data/endpoint reachable in the Internet, the whole process happens automatically near real time and there is no human involvement at all.

  • How to ensure the returned data is untampered?

    DOS Network applies Verifiable Random Function (VRF) and Threshold Cryptography to drive the secure, unpredictable and verifiable random group selection. Different oracle requests will be handled by randomly selected worker groups.

    Threshold cryptography will then be applied in the worker group to collectively generate a proof to demonstrate data integrity. Finally, the proof along with the data will be sent back together to the system contracts within one transaction for on-chain verification - any malicious submitter will be detected and punished accordingly.

    You can check our whitepaper for more technical details and mathematical proofs.

  • How fast is DOS Network?

    The off-chain process is blazing fast and usually completes within less than 1 second, including event monitoring, request processing, data fetching and parsing, collective proof generation within group members, etc. That is to say, the performance bottleneck is often in the layer 1 blockchain side.

    For Ethereum, the response is delivered in the next block (average block time ~14s) - the fastest one could achieve in theory. For other blockchains such as EOS (average block time ~0.5s) the delay will be much smaller.

  • Does DOS Network have tokens in the system? What role does it play?

    Yes, DOS Network has its own network token. Here's what it is used for:

    • Node operators deposit certain amount of tokens before joining the network to provide oracle services and earn fees and rewards. Malicious node operators will be detected and their stake will be forfeited as punishment.
    • Oracle service requesters need to pay fees to node operators. Fees could be paid both in a pay-per-use pattern and subscription-based way. DOS token is one of the first accepted payment tokens, with stablecoins to be supported in near future.
    • DOS token grants governance rights that node operators and token holders have right to vote for future accepted payment tokens and other proposals.
    • In the long term, once premium data feeds and marketplace is integrated, requesters also need to pay fees to requested premium data providers.
  • How does the system defend against sybil attacks?

    To prevent attackers from easily faking identities, node operators must deposit and lock network tokens in the system contract before joining the network and earning rewards. Verification is performed in the contract side, with malicious attackers failing verification process to be detected and punished. This makes sybil attacks expensive and nearly impossible and ties node operators' interests to the network and token values.

  • Who can run a node to join DOS Network? Why do they want to run a node?

    DOS Network is a permissionless peer-to-peer distributed network. It is a layer 2 network that can support multiple mainstream blockchains. Anyone can run the client software to join the network and earn rewards after depositing certain amount of network tokens.

    In order to quickly bootstrap the network and incentivize early node operators, in addition to the normal request processing fees, a PoS-like mining program will be started with 35% of total network tokens reserved as mining rewards. We'd like to distribute the majority percentage of tokens required to run a node to interesting and potential node operators. More information about fairer and wider token distribution as well as exact number of tokens and execution environment needed to run a DOS node will be released in future announcements. Moreover, node operators will be entitled to the governance and voting rights of the network and ecosystem.

  • Why is the node-selection mechanism based on randomness instead of reputation?

    We see some oracles are based on reputation to choose service nodes - node with higher reputation often leads to a bigger probability of being selected. However, reputation based solution is susceptible to centralization, collusions and targeted attacks against high-score nodes. Moreover, it easily leads to the Matthew Effect, disincentivizing new node operators with same abilities to join the network, leading to the centralization spiral.

    Thus we're relying on randomness to select oracle nodes. Randomness is specifically important in blockchains. For example, Proof-of-Work system achieves random block producer selection through the mining process. Verifiable Random Function (VRF) and Threshold Cryptography generate secure, unpreditable and verifiable randomness, keeping the DOS Network resistant to targeted attacks and node collusions, safe and fair for all node operators.