Interpretation of Arweave White Paper Version 17 (1): The Crossing of Space and Time

Author: PermaDAO

After several previous articles laying the groundwork for the iteration of Arweave's consensus mechanism, friends who follow Arweave must have a relatively intuitive understanding of the consensus mechanism of this protocol. However, I have always had a small doubt: since version 2.6 is so milestone-worthy, why doesn't its consensus mechanism have a specific name? (I previously referred to it as the throttled SPoRA mechanism). With this question in mind, I had an in-depth discussion with the core consensus mechanism engineer from Arweave and learned that SPoRes, the Simple Proof of Replication, is actually the name of Arweave 2.6's consensus mechanism.

Well, that also means that the 17th version of the white paper titled "Arweave: The Permanent Information Storage Protocol," released by the official team on December 26, 2023, is essentially the official explanatory document for Arweave 2.6, although by then the version number had already reached 2.7.0. The good news is that the previous articles "Understanding the Iteration of Arweave's Consensus Mechanism in One Article" and "Arweave 2.6 May Align More with Satoshi Nakamoto's Vision" have basically covered the important content of the Arweave mechanism. For those who want a brief overview, this is sufficient.

However, I still decided to provide a more in-depth chapter-by-chapter interpretation of the 17th version of the white paper, which is necessary for advanced Arweave participants. Because if you read it, the plethora of mathematical formulas and modeling proofs can be daunting, but perhaps this is the best expression of the beauty of the protocol.

White paper link: https://www.arweave.org/files/arweave-lightpaper.pdf

Crossing Space and Time

The invention of printing has had a profound impact on human civilization. Its emergence dramatically increased the speed of information dissemination and expansion, culminating in the peak reached by the internet at the end of the 20th century. The efficient spread of information has increased societal transparency and facilitated the awakening of individual consciousness. Nevertheless, the internet is still controlled and censored by centralized institutions, and the information silos created by the intent to manipulate the flow of information through centralized distribution are currently the biggest problems faced by individuals. Each year, a certain proportion of useful information is lost as a result.

The birth of Arweave carries the mission of solving this problem. At the beginning of its white paper, the Arweave protocol is clearly defined as:

A protocol for transmitting information in a disintermediated form across the dimensions of space and time.

Here, two dimensions are mentioned: space and time. Unlike 99% of data storage services on Earth, it acts like a "time capsule," not only carrying information data but also incorporating the important dimension of time.

By combining these two aspects, the Arweave protocol takes the form of a permanent information storage system. The term "permanent" has multiple definitions: the Oxford English Dictionary defines it as "continuing to exist or lasting for an indefinite period," while Merriam-Webster defines it as "continuing or enduring without fundamental or marked change."

Based on these two definitions of permanence, Arweave should store data for as long as possible, and the data must not change. To achieve this goal, the Arweave protocol is built on three core principles:

• Cryptographic Proof of Storage: A simple cryptographic proof system used to verify the replication and accessibility of data.
• Storage Endowment Fund: A predictable, self-executing endowment fund that pays for permanent storage using the deflationary effects brought about by technological advancements over time.
• Incentive Evolution: Allowing the protocol to have a healthy iterative mechanism over the long term by generating and rewarding non-mandatory network upgrades.

The primary means of achieving these principles is through the new blockchain consensus mechanism called Simple Proof of Replication (SPoRes), which aims to maximize decentralization while minimizing computational costs and bandwidth requirements. Together with the storage endowment fund, it establishes a model that incentivizes data replication and storage, allowing the network to operate autonomously, transparently, and predictably for hundreds of years.

Adjustments to Satoshi's Consensus

Decentralized consensus is a subfield of distributed computing that encompasses the important study of how participants in a network, even those in competition, can reach a consensus on a particular state. This subfield gained widespread attention with the emergence of Bitcoin's "Satoshi Consensus," which first allowed for consensus to be reached in a competitive and permissionless environment. Due to this innovation, Bitcoin created the first digital currency that does not rely on centralized human actors to manage monetary policy and has been operating well for over a decade.

Arweave draws inspiration from Bitcoin's proof-of-work mechanism for achieving consensus and has made some adjustments to align it with the goal of permanent storage of information within the network.

Arweave is a global decentralized consensus system composed of "nodes" that collectively store multiple copies of all data uploaded to the system. Users wishing to store information on Arweave pay a one-time storage fee to the network's storage fund and upload the corresponding data by transmitting it to the nodes within the network. Whenever a node successfully mines (confirms) a block, the nodes periodically reach consensus on the data that has newly entered the globally distributed database network. A block contains a list of transactions, each of which may include new data to be stored on the network, a transfer transaction of its cryptocurrency $AR, or both. Mining refers to the process by which each node verifies the storage status of previously uploaded data while accepting new data into the network. After confirming a block containing transactions, nodes "pull" the data they wish to replicate for mining from other nodes in the network.

Principles of Protocol Design

The two main principles of this protocol design are:

• Minimalism: The protocol design aims to maintain directness and minimal subjective judgment to facilitate as broad a network consensus as possible. Arweave only uses well-tested cryptographic primitives when constructing its data structures and algorithms.
• Optimization through Incentives: The protocol is not primarily aimed at prescribing the expected behavior but rather at incentivizing participants to achieve their ideal outcomes. Therefore, the specific mechanisms for achieving these outcomes will emerge naturally and evolve over time.

The Arweave protocol focuses solely on the vision of permanent and scalable data storage. Under this minimalist and focused design principle, applications built on the protocol have high scalability and composability, and the range of applications on the network has become broader and more diverse. This has led to a surge of decentralized smart contract platforms, databases, and applications in recent years. Additionally, Arweave's efficient proof system has very low requirements for hardware and bandwidth, maximizing network participation and decentralization.

The incentive measures for efficient mining in Bitcoin have led to significant improvements in hash computation speed and cost reduction, and the optimization driven by incentives is also very effective. Taking the Bitcoin network as an example, Bitcoin rewards miners for discovering a random number (nonce) that, together with a candidate block, produces a hash value below a certain specific threshold (difficulty level). This incentivizes miners to continuously seek ways to compute the maximum number of hashes at the lowest cost, leading to the development of dedicated ASIC miners, which have increased the number of hashes computed per second by 10^13 times since 2011. This growth rate is even faster than Moore's Law (10^10) during the same period. Furthermore, this has resulted in a 1 million-fold decrease in the cost per hash in the Bitcoin network during the same period, as illustrated in the graph. Therefore, inspired by this principle, we have adjusted Bitcoin's incentive mechanism in the Arweave protocol to incentivize participants to optimize solutions for storage proofs and data transmission issues.

This is the mechanism design principle behind the Arweave protocol based on considerations of space and time. The next article will systematically interpret the very core part of the white paper—how the cryptographic proof of storage is achieved.