Subspace Network turns decentralized storage as the new concept for Farmer’s Dilemma

As the crypto world existed many initiatives of consensus algorithms but in general, everything we got today all originated from PoW(a legendary consensus of "the God of Father coin" - Bitcoin) and gradually evolve into PoS until the present day. It is not an exaggeration to say that blockchain consensus space existing 2 kinds of things: PoW or PoS and the rest. Each consensus algorithm solves the problem in which team/project design to tackle the challenge. However it seems that the crypto industry at moment is witnessing many product/project or even platform states it decentralized at the WhitePaper at the beginning but actually move backward to centralization, more or less by using PoW, PoS, or any Po...X. Still, blockchain solution come in with Proof-of-Capacity consensus, Subspace makes it differential to change your mind of decentralization of blockchain.

What is Subspace Network?

Subspace Network, a Polkadot-focus product built by Subspace Labs. Project initiative is based on original research funded by the US National Science Foundation in 2018 and is currently being built using the Substrate framework. Subspace made up of a global team of protocol hackers, researchers, and engineers. Their goal is to solve systemic challenges in the blockchain space regarding sustainability, scalability, and fairness so that the crypto industry can return to its decentralized roots.

Subspace is the first PoC blockchain that resolves the farmers' dilemma, a set of subtle mechanism design challenges which suggest existing PoC blockchains are not actually incentive compatible.

The farmer’s dilemma states that in any PoC blockchain a consensus node must choose between either maintaining the blockchain state and history or maximizing the amount of space they pledge towards consensus. Rational farmers will always choose the latter, at best becoming a light client, while at worst joining a trusted farming pool. In other words, unlike PoW and PoS networks, there are strong financial incentives to not run a full node, meaning that PoC networks are actually more prone to centralization.

Within the Polkadot ecosystem, Subspace solves three critical problems:

1. It allows for a shared history of all parachains. While the relay chain provides shared security, each parachain is responsible for maintaining its history. Subspace provides a standard archival storage layer to ensure the history of each parachain is retained indefinitely and remains accessible under a standard retrieval API.
2. It allows for simple off-chain storage. Parachains may offload non-essential contract states, such as a video or image file associated with an NFT, to Subspace while retaining the same guarantees of persistence, immutability, and availability, at a fraction of the cost.
3. It allows for asynchronous cross-parachain storage. Using XCMP, parachains may snapshot and offload the state of any smart contract to Subspace and later retrieve the contract state when it is needed for computation.

What is Proof-of-Capacity (PoC) Consensus?

Proof-of-Capacity (PoC) is the leading alternative to Proof-of-Work (PoW) and Proof-of-Stake (PoS) based consensus. In a PoC blockchain, compute-intensive mining is replaced with storage-intensive farming. The key benefit is that farming is energy-efficient (and environmentally sustainable) while having security properties more similar to PoW than PoS. Farming also has the potential to be ASIC-resistant, allowing ordinary users to participate in consensus with commodity hardware, although this depends heavily on the implementation of the underlying proof-of-capacity.

PoC on Substrate

Subspace will be a parachain on Polkadot by using Substrate. Substrate supports pluggable consensus and ships with several existing algorithms: proof-of-stake, proof-of-authority, proof-of-work. Thanks to W3F grant, we can extend above list to support proof-of-capacity. To achieve this goal, Subspace has developed a set of Substrate modules that support an abstract notion of PoC consensus. These modules are designed to act as a middleware layer between an underlying PoC and an overarching Substrate Pallet which defines the specific on-chain logic.

Guaranteeing Safety & Liveness

Recently, Subspace has delivered Spartan V3 which focus on security analyst, here is some of the assumptions:

1. Spartan (and Subspace) may be treated as a secure extension of a Nakamoto-style or longest-chain consensus protocol, originating with Bitcoin under PoW, extended to Ouroboros Praos under PoS, as (largely) implemented in BABE and refactored for Spartan PoC.