Explained: Blockchain Oracles

The Coin Times
3 min readApr 6, 2022
Explained: Blockchain Oracles

Data and financial transactions are now recorded, stored, exchanged, and managed in new ways thanks to blockchain technology. Data is stored in a “chain” of “blocks,” one after the other. The distributed ledger is replicated across all nodes in the blockchain network

. Changes made to the ledger are instantly viewable by other network members, which is interesting. All agents in the network are alerted to new transactions as soon as they begin.

After that, miners use a proof-of-work technique to carry out verification and auditing activities. The necessity for blockchain oracles, on the other hand, arose as a direct result of the blockchain’s own flaws.

Devices and entities connected to the blockchain can be referred to as “Blockchain Oracles.”

Even though the concept of decentralised oracles has been around for some time, there is still discussion regarding how to put them into practice and whether or not they can be relied upon or not.

Oracles serve as intermediaries between the blockchain and our physical reality. They serve as on-chain APIs that you may use to get data for your smart contracts. It might be anything, from the pricing of a product to the forecast of the weather.

Oracles may also be used to “send” data into the real world, in the form of two-way communication. Oracles use online APIs or market data feeds to obtain and validate external data for use in blockchains and smart contracts.

Price feed information, weather conditions, and even random numbers for gaming are examples of data that smart contracts may demand.

In order to interface between the blockchain and a data feed, oracles may be used to ask a particular question of the data source and then link to the results. Because of this, smart contracts may operate depending on the data coming in from the stream.
What exactly is a decentralised oracle?
A decentralised oracle, also known as a decentralised oracle network, is a collection of autonomous blockchain oracles that supply data to a blockchain. In the decentralised oracle network, each independent node or oracle receives data from an off-chain source and delivers it on-chain. This data is then pooled such that the system may arrive at a deterministic truth value for that data point. The oracle issue is solved by decentralised oracles.
What is a Blockchain Oracle’s Process?
Blockchain oracles, in contrast to popular belief, do not rely on outside sources of data for their information. External data sources may be queried, verified, and authenticated using a blockchain oracle as a layer. A blockchain oracle then communicates this information to the blockchain in a way that the blockchain can interpret. Temperature data, pricing information, or the specifics of a successful transaction might all be sent via Oracles.


A smart contract must be invoked and network resources used in order to get external data. Some oracles also have the capability of delivering and receiving information through smart contracts and other external sources. Accordingly, there are many distinct types of blockchain oracles that may be used for various purposes.
The difficulty of the oracle
Ethereum transactions are unable to directly access off-chain data. However, a smart contract’s decentralisation is nullified if it relies on a single point of truth for its data. The oracle issue refers to this.

By employing numerous data sources, we can avoid the issue of the oracle. If one piece of data is hacked or collapses, the smart contract would continue to work as intended.
To have a long-term impact in practical applications and diverse sectors, blockchains must be able to interact with real-world data correctly and consistently. With oracles, this is a complex task that offers several obstacles. A great amount of development has already been done with regard to connecting blockchains to other data sources, which will constitute a tremendous leap forward for the technology.