Consensus Décentralisé - Blockchains - Smart Contracts - Decentralized Consensus

Ledger, the French company known for its range of bitcoin hardware wallets, has launched a new extension of its product line: the Ledger Blue.
Billed as "the most advanced hardware wallet on the market today", the Ledger Blue is a significant departure from the thumbdrive style of Ledger's previous products. With a 320 x 480 pixel screen (along with BlueTooth and near-field communication (NFC) capability), it's a handheld touchscreen device that can run a number of different applications.
In a video call, Ledger CEO Eric Larchevêque talked to CoinDesk about the product’s evolution, design philosophy and target market.

Blockchain applications live in their own digital realm, totally orthogonal to the “meat space” also known as the Real World™. Be it decentralized application or smart contracts, their reach is limited to the space they can control. Any use case projection in our reality eventually confronts the following hard fact: how can an app efficiently and securely interact with the physical world?

We need gateways to input/output with the physical realm, which are also called “oracles”.

Oracles are trusted entities signing claims about the state of the world.

Depending of what exactly we call the “physical world”, and depending of the existence or not of a consensus about the state of what we need to assess, there are different implementation of Oracles.