Topic: [Whitepaper] 👁️ Witnet: A Decentralized Oracle Network Protocol 👁️ (Read 342 times)
December 11, 2017, 10:24:30 AM
December 11, 2017, 10:16:03 AM
TL;DR: A network protocol enabling smart contracts to consume data feeds from the web.
Hi BT community, here Adán from Stampery (those crazy guys offering user friendly data timestamping since 2014 using BTC, LTC, ETH & ETC) [1].
Over the last months, we've been doing thorough research on the state of contracts and oracles and just published a research/position paper [2] on how Stampery devises a protocol for bridging the gap between deterministic contracts and the undeterministic web.
We won't be necesarily building the proposed network/protocol. This is just a request for comments oriented to collect feedback from the applied crypto community.
Problem
Current smart contract solutions are self-contained in their supporting blockchains and have very little capability to interact with other blockchains, the Internet and the rest of the world.
External information can be fed into smart contracts using an oracle: a trusted entity which sign claims about the state of the world. But that approach puts trust in a single third party, so it's not trustless nor tamper-resistant and therefore leaves space to contestation, repudiation and tampering.
Mission-critical smart contracts aren't viable without decentralized and trustless oracles.
Solution
The Witnet protocol is Decentralized Oracle Network (DON) built on a blockchain with a native token called Wit.
This network is made of automated "witness nodes" that accept requests for retrieving and attesting web contents. These witnesses earn Wit tokens when they perform their work honestly.
Witnet's claims are trustworthy not because of any kind of authority but because they're made by combining all the claims coming from a big number of anonymous witnesses who are incentivized to be honest and compete against each other for rewards.
Workflow
More info
The Witnet whitepaper explains all these incentives, algorithms, security considerations and network protocols in detail; as well as many other features such as fact cross-checking, native smart contracts, merkelized abstract syntax trees and covenants.
The PDF is freely available at Cornell's University arXiv e-print service: [2].
Use cases
E-commerce
As a consumer, Alice wants to buy a computer from Bob without blindly trusting him, so that she doesn't lose her money if the shipment never arrives.
As an online retailer, Bob wants to directly transact with consumers like Alice without the need for an intermediary who would charge him an abusive fee.
Alice can send her payment to a Witnet-powered escrow smart contract that queries the courier company’s API and will only release the funds to Bob as soon as the shipment has been delivered to her by a certain date.
If Alice does not receive the shipment on time, she will be able to get a refund from the Witnet-powered escrow smart contract.
Outcome-conditioned value transfer
Alice and Bob want to transmit each other a certain amount of value depending on the outcome of a certain event—be it the result of a sports match, a political election, etc—without blindly trusting each other and without the use of intermediaries.
They can deposit value in a Witnet-powered smart contract that will query for the outcome of a future event and allow Alice or Bob to spend the total deposited value depending on such outcome.
Automated bug bounty programs
As an open source software project leader, Alice wants to encourage third party developers to solve bugs in the code base.
Alice can set a bounty in a Witnet-powered smart contract that watches the result of a certain unit test or functional test and rewards whomever submits a pull request on GitHub that will make such test pass successfully.
Web archiving
Alice, Bob and Carol want to make sure that a web content remains available forever, because of its historic relevance or for any other reason.
They can set up a Witnet-powered smart contract that will retrieve such web content, get it attested and finally delivered to a decentralized storage network (DSN) such as Filecoin.
The content will be kept stored and available in the DSN as long as Alice, Bob, Carol or any other interested party keeps funding the smart contract so that it can automatically renew the storage contract.
Automated uptime SLA
As a technology startup, AliceInc can't afford to deploy their own server infrastructure, so they rather use a cloud provider called BobCorp to host their app backend.
Most importantly, what AliceInc can't afford is their app suffering any downtime, so they want BobCorp to agree on a certain uptime and automatically compensate them for any breach of such availability agreement.
BobCorp wants to provide an availability agreement (for a fee) that will automatically compensate their customers for any major outages without chance for contestation or litigation, so that their customers can't claim false downtimes.
AliceInc can pay to a Witnet-powered smart contract that locks the funds, checks the availability of BobCorp’s cloud platform at random intervals and unlocks fractions of the funds to BobCorp or refund them to AliceInc depending on availability.
Travel insurance
As a businesswoman who often flies for work, Alice needs to arrive at her destinations on time and not to miss important meetings, so she wants to make sure she gets a refund and if a flight is overly delayed or just cancelled.
As an airline, Bob Airways wants to offer an insurance policy that reimburses customers who opt-in for that policy (for a fee) if their flights get overly delayed or just cancelled. They want this service to be as cost-effective as possible, so they want to manage without an intermediary insurance company.
Alice can pay to a Witnet-powered smart contract that will lock the received funds. After a certain delay past the expected arrival date, the contract will automatically check if the flight arrived on time and transfer the funds to Bob Airways. If on the contrary the flight was delayed beyond the agreed threshold or it was cancelled, Alice will get her money back immediately.
This scheme encourages Bob Airways to offer better reliability in pursue of achieving higher earnings. For a stronger incentive alignment, if Alice pays a little more, Bob Airways will deposit a collateral in the smart contract in order to cover reimbursement for additional meal and hotel expenses.
Weather insurance
As a modest crop producer, the Alice & Sons Farming Company would be severely affected in case of a severe drought. They want to minimize such risk by using some kind of insurance scheme that indemnify them if the rainfall over a certain period is too low. However, they have no access to public crop insurance programs.
As an insurtech startup, BobSure wants to offer insurance products with reduced overhead costs, increased transparency and especially with a lower chance for contestation, litigation or fraud.
Alice & Sons Farming Company can pay a premium to BobSure for setting a Witnet-based smart contract that will query public weather services for precipitation records over a certain period and compensate the farming company in case of drought.
Beyond
External links
[1] https://stampery.com
[2] https://arxiv.org/pdf/1711.09756.pdf
Hi BT community, here Adán from Stampery (those crazy guys offering user friendly data timestamping since 2014 using BTC, LTC, ETH & ETC) [1].
Over the last months, we've been doing thorough research on the state of contracts and oracles and just published a research/position paper [2] on how Stampery devises a protocol for bridging the gap between deterministic contracts and the undeterministic web.
We won't be necesarily building the proposed network/protocol. This is just a request for comments oriented to collect feedback from the applied crypto community.
Problem
Current smart contract solutions are self-contained in their supporting blockchains and have very little capability to interact with other blockchains, the Internet and the rest of the world.
External information can be fed into smart contracts using an oracle: a trusted entity which sign claims about the state of the world. But that approach puts trust in a single third party, so it's not trustless nor tamper-resistant and therefore leaves space to contestation, repudiation and tampering.
Mission-critical smart contracts aren't viable without decentralized and trustless oracles.
Solution
The Witnet protocol is Decentralized Oracle Network (DON) built on a blockchain with a native token called Wit.
This network is made of automated "witness nodes" that accept requests for retrieving and attesting web contents. These witnesses earn Wit tokens when they perform their work honestly.
Witnet's claims are trustworthy not because of any kind of authority but because they're made by combining all the claims coming from a big number of anonymous witnesses who are incentivized to be honest and compete against each other for rewards.
Workflow
- Clients publish attestation requests to the network and attach tokens to reward the witnesses. The more tokens, the more witnesses will be employed. https://i.imgur.com/vkLKTkjl.png
- Every 90 seconds, attestation requests are randomly assigned to witnesses. Their chance to be assigned those tasks is proportional to their reputation (past performance in terms of honesty). https://i.imgur.com/qDQHCJHl.png
- Witnesses use a headless web browser to retrieve data from the web, apply transformations on the data as specified by the clients in their requests and commit their claims secretly. https://i.imgur.com/qEquVf4l.png
- Once all the witnesses who were assigned the same task have published their own commitments, they must disclose the actual value of their claims. https://i.imgur.com/POmWKltl.png
- Every 90 seconds, one of the witnesses wins the right to mine a block, Each witness' chance to be elected is again proportional to its reputation.
- Block-mining witnesses compare the claims and discard outliers (false claims) by applying sofisticated statistical techniques using the Truth-By-Consensus algorithm. https://i.imgur.com/raOCR8Yl.png
- Honest witnesses are rewarded reputation points and a fraction of the tokens from the attestation requests. In the other hand, dishonest and lazy witnesses lose reputation points. https://i.imgur.com/HV93WWul.png
- If requested, a subset of the witnesses called "bridges" step in and send true claims to other blockchains in exchange for tokens. They can also arrange eternal storage of the data. https://i.imgur.com/N3Tv3TOl.png
More info
The Witnet whitepaper explains all these incentives, algorithms, security considerations and network protocols in detail; as well as many other features such as fact cross-checking, native smart contracts, merkelized abstract syntax trees and covenants.
The PDF is freely available at Cornell's University arXiv e-print service: [2].
Use cases
E-commerce
As a consumer, Alice wants to buy a computer from Bob without blindly trusting him, so that she doesn't lose her money if the shipment never arrives.
As an online retailer, Bob wants to directly transact with consumers like Alice without the need for an intermediary who would charge him an abusive fee.
Alice can send her payment to a Witnet-powered escrow smart contract that queries the courier company’s API and will only release the funds to Bob as soon as the shipment has been delivered to her by a certain date.
If Alice does not receive the shipment on time, she will be able to get a refund from the Witnet-powered escrow smart contract.
Outcome-conditioned value transfer
Alice and Bob want to transmit each other a certain amount of value depending on the outcome of a certain event—be it the result of a sports match, a political election, etc—without blindly trusting each other and without the use of intermediaries.
They can deposit value in a Witnet-powered smart contract that will query for the outcome of a future event and allow Alice or Bob to spend the total deposited value depending on such outcome.
Automated bug bounty programs
As an open source software project leader, Alice wants to encourage third party developers to solve bugs in the code base.
Alice can set a bounty in a Witnet-powered smart contract that watches the result of a certain unit test or functional test and rewards whomever submits a pull request on GitHub that will make such test pass successfully.
Web archiving
Alice, Bob and Carol want to make sure that a web content remains available forever, because of its historic relevance or for any other reason.
They can set up a Witnet-powered smart contract that will retrieve such web content, get it attested and finally delivered to a decentralized storage network (DSN) such as Filecoin.
The content will be kept stored and available in the DSN as long as Alice, Bob, Carol or any other interested party keeps funding the smart contract so that it can automatically renew the storage contract.
Automated uptime SLA
As a technology startup, AliceInc can't afford to deploy their own server infrastructure, so they rather use a cloud provider called BobCorp to host their app backend.
Most importantly, what AliceInc can't afford is their app suffering any downtime, so they want BobCorp to agree on a certain uptime and automatically compensate them for any breach of such availability agreement.
BobCorp wants to provide an availability agreement (for a fee) that will automatically compensate their customers for any major outages without chance for contestation or litigation, so that their customers can't claim false downtimes.
AliceInc can pay to a Witnet-powered smart contract that locks the funds, checks the availability of BobCorp’s cloud platform at random intervals and unlocks fractions of the funds to BobCorp or refund them to AliceInc depending on availability.
Travel insurance
As a businesswoman who often flies for work, Alice needs to arrive at her destinations on time and not to miss important meetings, so she wants to make sure she gets a refund and if a flight is overly delayed or just cancelled.
As an airline, Bob Airways wants to offer an insurance policy that reimburses customers who opt-in for that policy (for a fee) if their flights get overly delayed or just cancelled. They want this service to be as cost-effective as possible, so they want to manage without an intermediary insurance company.
Alice can pay to a Witnet-powered smart contract that will lock the received funds. After a certain delay past the expected arrival date, the contract will automatically check if the flight arrived on time and transfer the funds to Bob Airways. If on the contrary the flight was delayed beyond the agreed threshold or it was cancelled, Alice will get her money back immediately.
This scheme encourages Bob Airways to offer better reliability in pursue of achieving higher earnings. For a stronger incentive alignment, if Alice pays a little more, Bob Airways will deposit a collateral in the smart contract in order to cover reimbursement for additional meal and hotel expenses.
Weather insurance
As a modest crop producer, the Alice & Sons Farming Company would be severely affected in case of a severe drought. They want to minimize such risk by using some kind of insurance scheme that indemnify them if the rainfall over a certain period is too low. However, they have no access to public crop insurance programs.
As an insurtech startup, BobSure wants to offer insurance products with reduced overhead costs, increased transparency and especially with a lower chance for contestation, litigation or fraud.
Alice & Sons Farming Company can pay a premium to BobSure for setting a Witnet-based smart contract that will query public weather services for precipitation records over a certain period and compensate the farming company in case of drought.
Beyond
- Prediction markets
- Fiat-pegged cryptocurrencies (stablecoins)
- Digital derivatives
- Letters of credit
- Digital inheritances
- Exchange insurance
- Much more...
External links
[1] https://stampery.com
[2] https://arxiv.org/pdf/1711.09756.pdf
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