Trusted Data Broker: Authenticated Data Feeds for Blockchains and Data Consumers

Short Answer Question

What is a smart contract? What role does it play in a blockchain system?

What problem does a Trusted Data Broker solve in blockchain data acquisition?

Briefly describe the two main components of a Trusted Data Broker and their functions.

What role does SGX (Software Guard Extensions) play in a Trusted Data Broker?

What is a "remote client device"? How does it interact with a Trusted Data Broker?

What does a "datagram" refer to in the context of a Trusted Data Broker?

How does a Trusted Data Broker ensure the confidentiality of data requests?

What role does "gas" play in the Ethereum blockchain?

What is "gas sustainability"? Why is it critical for Ethereum services?

Briefly describe two common techniques that can minimize the size of hybrid TCB (Trusted Computing Base) code.

Short Answer Question Answer

A smart contract is a computer program that automatically executes the terms of a contract. It is stored on the blockchain and automatically executes when preset conditions are met without the intervention of a third party. Smart contracts play an important role in decentralized applications, such as decentralized finance (DeFi).

Trusted data intermediaries solve the problem that blockchain smart contracts have difficulty in securely obtaining off-chain data. Due to the characteristics of the blockchain itself, smart contracts cannot directly access external data sources. Trusted data intermediaries act as a bridge to securely pass authenticated off-chain data to smart contracts.

The two main components of a trusted data intermediary are:

Secure enclave component: This is a trusted execution environment responsible for authenticating data obtained from the data source, such as using SGX technology.

Relay component: Responsible for communication between the secure enclave component and the outside world (including data sources, blockchains, and client devices).

SGX is a hardware security technology developed by Intel that allows the creation of isolated execution environments called "enclaves". In a trusted data intermediary, the secure enclave component usually uses SGX to protect the confidentiality and integrity of its code and data, preventing attacks from the operating system and other malware.

A remote client device refers to any device that is connected to a trusted data intermediary over a network, such as a user's laptop or mobile phone. A remote client device can send data requests to a trusted data intermediary and receive authenticated data.

A data packet refers to a data packet obtained from a data source and authenticated by a trusted data intermediary. It usually contains data obtained from a specific data source within a specific time period.

Trusted data intermediaries can ensure the confidentiality of data requests by:

Encrypting request parameters with the public key of the secure enclave component to prevent disclosure on the blockchain.

Securely access access-controlled online data sources using encrypted user credentials.

Gas is a unit used in the Ethereum blockchain to measure the computing resources required to execute smart contracts. Users need to pay gas fees for executing smart contracts to prevent denial of service attacks and incentivize miners to process transactions.

Gas sustainability means that Ethereum services always have enough gas to pay for the blockchain calls they initiate. Due to malicious users or code errors, services may run out of gas and become unavailable. Therefore, Gas sustainability is critical to the availability of Ethereum services.

Two general techniques that can minimize the size of hybrid TCB code are:

Binding off-chain trusted components to Ethereum wallets: By hard-coding the public key of the off-chain trusted component into the smart contract, expensive signature verification in the smart contract can be avoided.

Eliminate reliance on on-chain authentication: By validating the response parameters from off-chain trusted components in smart contracts, expensive authentication operations in off-chain trusted components can be avoided

Glossary of key terms

Blockchain: A decentralized, distributed ledger that records transactions and maintains data consistency.

Smart Contract: A self-executing contract stored on a blockchain that automatically executes when preset conditions are met.

Trusted Bridge: Acts as a bridge between the blockchain and external data sources, securely passing authenticated data to smart contracts.

Secure Enclave Component: The component in a trusted data broker responsible for authenticating data, typically using a trusted execution environment such as SGX.

Relay Component: The component in a trusted data broker responsible for communicating with the outside world.

SGX (Software Guard Extensions): Hardware security technology developed by Intel to create an isolated execution environment called an "enclave".

Remote Client Device: Any device connected to a trusted data broker over a network.

Datagram: A data packet obtained from a data source and authenticated by a trusted data intermediary.

Gas: A unit used in the Ethereum blockchain to measure the computing resources required to execute smart contracts.

Gas Sustainability: Ethereum services always have enough gas to pay for the blockchain calls they initiate.

Hybrid TCB (Hybrid Trusted Computing Base): A hybrid trust model across blockchains and trusted execution environments.