Zen Protocol Whitepaper

Decentralized platforms let their participants avoid counterparty risk
without using trusted intermediaries. The Zen Protocol is the basis
for such a platform. Zen is a parallel blockchain to Bitcoin, allowing
users to create assets that react to events on the Bitcoin network. Zen
targets financial use cases such as trading and creating new kinds of
assets. In this white paper, we discuss how Zen works, how it differs
from existing smart contract platforms, and what sort of applications
it makes possible.

Zen Protocol Website
Zen Protocol Whitepaper