DField SolutionsMérnöki stúdió · Budapest
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Oracle (blockchain)

Related service Blockchain & smart contracts

DEFINITION

A service that feeds real-world data — a price, a match result, the weather — into a smart contract, which otherwise can't see outside its own chain. A bad oracle is a classic exploit vector, so we treat its trust model as part of the audit.

RELATED TERMS06
  • Smart contract→

    Code running on a blockchain (Solidity, Rust) that auto-executes an agreement. A single bug can cost nine figures · why we audit, fuzz, and threat-model before deploy.

  • Solidity→

    The primary language for EVM-compatible blockchains (Ethereum, Arbitrum, Base). Pascal-like syntax, low-level memory handling, TS-compatible toolchain (Foundry, Hardhat).

  • EVM (Ethereum Virtual Machine)→

    The shared execution environment across Ethereum and compatible chains (Arbitrum, Base, Polygon, Optimism). Writing a contract here means it runs on all of them.

  • L2 (Layer 2)→

    A secondary network (Arbitrum, Base, Optimism, zkSync) settling on Ethereum (L1) but much faster and cheaper. Rollups bring 10–100× lower gas.

  • Invariant test→

    A test that verifies a universal rule ('sum of user balances always equals total supply'). Feeds the contract random transaction sequences; the rule must hold in every state.

  • Fuzz test→

    Running millions of pseudo-random inputs through a function to find a combination that breaks it. Echidna or Foundry fuzz campaigns.

MENTIONED IN THE BLOG08