  We present Fission, a new permissionless blockchain that achieves scalability
in both terms of system throughput and transaction confirmation time, while at
the same time, retaining blockchain's core values of equality and
decentralization. Fission overcomes the system throughput bottleneck by
employing a novel Eager-Lazy pipeling model that achieves very high system
throughputs via block pipelining, an adaptive partitioning mechanism that
auto-scales to transaction volumes, and a provably secure energy-efficient
consensus protocol to ensure security and robustness. Fission applies a hybrid
network which consists of a relay network, and a peer-to-peer network. The goal
of the relay network is to minimize the transaction confirmation time by
minimizing the information propagation latency. To optimize the performance on
the relay network in the presence of churn, dynamic network topologies, and
network heterogeneity, we propose an ultra-fast game-theoretic relay selection
algorithm that achieves near-optimal performance in a fully distributed manner.
Fission's peer-to-peer network complements the relay network and provides a
very high data availability via enabling users to contribute their storage and
bandwidth for information dissemination (with incentive). We propose a
distributed online data retrieval strategy that optimally offloads the relay
network without degrading the system performance. By re-innovating all the core
elements of the blockchain technology - computation, networking, and storage -
in a holistic manner, Fission aims to achieve the best balance among
scalability, security and decentralization.
