  This document is a specialized technical description of one of the potential
implementations of a second layer protocol over Gravity, a
blockchain-/token-agnostic decentralized oracle protocol. The SuSy protocol
prescribes an implementation of cross-chain transfers of digital assets
(tokens) in blockchain networks that support smart contracts, focused primarily
on popular blockchains with varying architectures, consensuses and
cryptography. SuSy is centered exclusively around technical implementation of
transfers, without bringing any incentive models for cross-chain transfer
providers. In addition, we describe the most popular inter-chain communication
solutions such as Polkadot, Cosmos Hub, Rainbow and RenVM, as a backdrop for
the new solution proposed in this paper.
