Press Release

PoWacle: a decentralized blockchain price oracle

Blockchain oracles are systems that connect blockchains with
the outside world by interfacing with external data providers. They pro-
vide decentralized applications with the external information needed for
smart contract execution. In this paper, we focus on decentralized price
oracles, which are distributed systems that provide exchange rates of
digital assets to smart contracts. They are the cornerstone of the safety
of some decentralized finance applications such as stable coins or lending
protocols. They consist of a network of nodes called oracles that gather
information from off-chain sources such as an exchange market’s API and
feed it to smart contracts. Among the desired properties of a price oracle
system are low latency, availability, and low operating cost. Moreover,
they should overcome constraints such as having diverse data sources
which is known as the freeloading problem or Byzantine failures.
In this paper, we define the distributed price oracle problem and present
PoWacle, the first asynchronous decentralized oracle protocol that copes
with Byzantine behavior.