Engineering Filecoinʼs Economy
2020-08-27

The Filecoin Network and its mission
As a novel data storage and distribution network, the Filecoin Networkʼs mission is to create adecentralized, efficient, and robust foundation for humanityʼs information. This mission will
be advanced by incentivizing consistent growth and development of the Filecoin Networkʼseconomy. The goal of the economic design is to align incentives and pragmatically reward
useful and reliable storage with as few rules as possible. The action and interaction of each ofthese mechanisms must be considered during the design process. Other economic structuresand product offerings can then emerge from these basic building blocks. This document
explains specific incentive mechanisms and economic stimuli provided by the protocol itself.
For each fee, reward, or penalty in the protocol, there will be an explanation of how it isintended to contribute to long-term utility of the network.
Additionally, this document explains the importance of long-term cooperation between
participants in the Filecoin Network. The protocolʼs design enables and incentivizes thiscollaboration and furthers the interests of all participants.
The remainder of this document explains:● Why the Filecoin Network has a strong value proposition; (Section 1)● What it means to build an economy and a market from that business model; (Section 2)● How that market handles data storage; (Section 3)● The role that storage clients play in that market and the Filecoin Protocol; (Section 4)● How the protocol retrieves and delivers data; (Section 5)● The role of the filecoin token as a medium of exchange in the economy; (Section 6)● The current economic structures and initial parameters of the Filecoin Protocol;(Section 7)● Key planned improvements that may drive future growth of the network. (Section 8)

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Engineering Filecoinʼs Economy

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The Filecoin Network and its mission

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1. The future of the data storage and distribution industry

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2. The Filecoin Economy

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2.1 A Market for Data

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2.2 An Export Economy

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2.3 Participants in the Filecoin Economy

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3. Storage Services on Filecoin

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3.1 What is a sector?

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3.2 Sealing Sectors

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3.3 Lifecycle of a Sector

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3.4 Miner Collaterals

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3.4.1 Initial Pledge Collateral

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3.4.2 Block Reward as Collateral

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3.4.3 Storage Provider Deal Collateral18

3.5 Redundancy

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3.6 Fast retrieval

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3.7 Offline data transfer

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4. Power of a storage client

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4.1 Client lifecycle

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4.2 Deal proposals

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4.3 Deals

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4.4 Verified clients22

5. Content delivery on Filecoin

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6. Demand and supply of the filecoin token

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6.1 Network Baseline

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6.2 Token Allocation

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7. Initial parameter recommendation

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8. Growth and governance of the Filecoin Network33

8.1 Upcoming features

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8.2 Governance and improvement33

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1. The future of the data storage and distribution industry
Filecoin is a decentralized data storage and distribution network; it is therefore necessary todescribe what it means to be a digital storage network. Cloud storage has evolved into anindustry valued at ​over $46B​ in 2019​, where data is stored in enormous data centers far fromend users, where space and utility costs are low. Content delivery networks (CDNs) thenacquire space and pack servers in dense population centers to cache content nearer to users,
and are, as an industry, valued at ​over $12B​. The rate at which we generate data is growing as
video and images supplement text, resolution grows, and the number of internet-accessible
devices increases. The growing amount of data stored globally is depicted in Figure 1. And the
top five storage providers control ​77 percent ​of the global IaaS market, making it difficult for
new market entrants to compete. Any new entrant to the market must compete against the
reputation, infrastructure, and potentially network effects possessed by existing providers.
Without a single platform for coordination and collaboration, small entities cannot effectively
compete with the capacity, scale, and reputation of existing providers.

Figure 1. Size of the global datasphere by year [​source​]
The data itself sits on a spectrum of access. Most data is never read; users simply want to knowthat they ​can​ access that document, photograph, record, or footage if the need arises.
Alternatively, some data is accessed very frequently, or goes viral, and must be replicatedacross the internet to be readily available to requesters with low latency.
Just as Airbnb allows homeowners to compete with hotels, the Filecoin Protocol will allow any
willing and able storage provider to join a storage network and offer their storage for sale,
while offloading auxiliary tasks like tooling, documentation, and branding to the Filecoin

3Network itself. At first, the network will be best adapted to infrequently read files, optionally
supporting fast retrieval at a clientʼs request; the number of use cases will grow as the network
grows, as the protocol evolves, and as tools are built. Even at network launch, however, theFilecoin Network has a unique value proposition:
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Verifiable storage​ – Rather than needing to trust a cloud storage provider or rely on
legal recourse, the Filecoin Protocol cryptographically verifies whether or not clients'
data are being stored.
Open participation​ – Anyone with sufficient hardware and an internet connection canparticipate in the Filecoin Network.
Distribution of storage empowers local optimization ​– Driven by open participation,market forces in the Filecoin Economy should communicate information more
efficiently and the network will be more responsive than centralized storage
platforms. The website or video a client requested could be hosted as close as theFilecoin Mining node next door. This will increase the utility of the network by
ensuring that data can be stored near the network edge, close to the clients, in a costeffective way.
Flexible storage options​ – Because the Filecoin Network will be an open platform, thenetwork will support many additional tools and auxiliary services provided by thecommunity of developers improving or building on top of the protocol.
The network has been built by a community​ – Filecoin will be stronger because it
provides participants the opportunity to obtain stake in the networkʼs success. Filecoin
participants will benefit by working together to improve the Filecoin Network.

Given the growth of both demand and supply, a decentralized storage networkʼs differentiatedapproach to cloud storage could unlock significant efficiency improvements and growth.

2. The Filecoin Economy
Filecoin is more than a network; the protocol lays the groundwork for a market economy built
around a marketplace for the storage and retrieval of data. Unprecedented growth of the
network will require unprecedented collaboration between researchers, engineers,
stakeholders, miners, and clients in this market economy, as the network adapts and grows toaccommodate additional use cases.

2.1 A Market for Data
In general, markets balance supply and demand, determining the prices at which goods orservices trade. In the case of Filecoin, if you have extra storage and computing power, you may
be willing to provide it to others for a fee - while those seeking data storage may be willing to
pay for storage services. Aligning these two prices would result in a deal (i.e., a market clearing

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transaction). Creating a marketplace allows consumers and providers to come together andexpress how much they value commodities. In thriving economies, there are so-called "gains
from trade," where trades increase the net utility (or happiness) of both participants.
As a global digital marketplace, it is necessary to choose at least one valid currency fortransactions. Because Filecoin is a permissionless market with cryptographically verifiable
goods, design constraints could only be satisfied with a native token, the filecoin (FIL). This
token acts as a medium of exchange, facilitating transactions and production activities,
somewhat similar to the in-game currencies of virtual economies in multiplayer online games.
However, as a currency, the token also acts as a store of value; its minting must be tied toadding utility to the network. The interactions underpinning this digital storage market are
illustrated in Figure 2.

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Figure 2: Basic client-miner interaction sequence: clients propose deals to miners, miners
accept deals, data transfer occurs, miners seal deal data into sectors, miners prove their sectors
and start earning block reward, clients retrieve files from miners.

2.2 An Export Economy
Filecoinʼs export economy is most easily understood by considering the metaphor of an island
economy producing valuable goods and services from raw materials. Trades are executed in
the islandʼs currency, which must be purchased to make trades. Inhabitants of the island
participating in trade need to deploy capital in this currency to engage in productive activities;
typically this deployment is investment in capital assets, while in the case of Filecoin, this takes
the form of mining hardware and collateralized tokens.

Figure 3: Illustration of the Filecoin Economy where raw materials (electricity, disks,algorithms, data centers, labor, compute resources, software, etc) are converted into valuable
storage services to be traded with the outside world.

6Given the nature of Filecoinʼs Economy, the protocol must generate its own currency. The
creation of new tokens can facilitate more trades and stimulate the economy, but if supply
grows too quickly, it may harm the economy. Ideally, the rate of token minting should
approximately match the rate of value creation, which provides a clear mandate for the
protocolʼs token generation rates. Value is created as goods are traded (i.e. supply clears withdemand, creating gains from trade). Filecoinʼs minting function tries to approximate this value,in the absence of a reliable and incentive-compatible measure of economic surplus.
The overarching goal for the whole economy, researchers, miners, developers, clients, is tomake the production as efficient as possible and make the network as attractive as it can be to
the outside world. An economy producing more valuable goods more efficiently will lead tomore demand for the goods and more demand for the networkʼs token. Malicious participantsin the Filecoin Economy, who attempt to exploit the protocol, will drive real demand awayfrom the economy and destroy value, harming all members of the economy, like thieves
plundering in the island economy. As a result, the goal of all participants should be to get realpaying demand for the goods that the network produces - key to a thriving economy that canoperate with little or no subsidies. In the long term, the Filecoin Network must be a protocol
where demand from clients is so strong that mining is still profitable with little or no block
reward. Figure 3 illustrates an example of an export economy where miners amass disks, data
centers, compute resources with algorithms developed by researchers and applications andtooling built by developers to produce useful storage goods and services for storage clients.

2.3 Participants in the Filecoin Economy
Within the Filecoin Economy, there are three distinct markets, and participants in the network
exchange different goods or services. In the storage market, storage miners offer to rent out
digital storage that will be verified by the Filecoin Network. Conversely, storage clients offer
filecoin to have their data stored. This storage is priced based on the amount of storage spaceused and the duration of the contract in time. There is a retrieval market, where clients pay
filecoin to retrieval miners to provide them with a copy of the data. Lastly, token exchanges
could enable participants to trade to put filecoin in the hands of clients, miners, and othertoken holders. The five primary stakeholder groups, as well as the common interactions
between them, are illustrated in Figure 4.

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Figure 4: Illustration of different network participants and common sample interactions. Notethat an individual or entity can take on multiple roles. For instance, anyone in possession of
filecoin would be considered a token holder.
The participants mentioned above must work together to support the growth of the Filecoin
Economy. And thereʼs one more major ecosystem partner participating in this economy: theFilecoin Foundation. The Filecoin Foundation is separate from Protocol Labs and is fundedwith tokens from the genesis block allocation. It will deploy those tokens to guide the network
towards its mission of building a robust and growing network for humanityʼs data.
Collaboration across participants is required to make Filecoin a robust and efficient economy
in producing valuable storage-related goods and services. Some participants may join
temporarily to exploit subsidies from the protocol. However, the protocol is designed so thatrational decisions are aligned with the creation of value for the network; therefore their profits
are increased if they join the network and participate on long time horizons. The

8permissionless nature of the protocol should thus result in a virtuous cycle, drawing in newparticipants, incentivizing continued participation, and making future growth self-sustaining.
Existing and mechanisms are described in the remainder of the document. With enoughentrepreneurs and engineers that see the potential of a decentralized storage network, thesubsidies will empower participants and accelerate the rate at which the community can builda thriving economy that can operate with little or no subsidies.
Given the permissionless nature of the network, the rules and parameters must incentivize
participant alignment with the long-term goals and mission of the network. It is possible to rely
on trust in a small community. But in order to support permissionless, pseudonymousinteractions, rules must be enforceable with cryptography and aligned with incentives. As a
distributed storage network, the Filecoin Networkʼs value is fundamentally determined by its
ability to deliver long-term, reliable, and useful storage. As a result, a community of rational
actors will lead to a network where real value is created, as clients are drawn to thefunctionality of the network, and they purchase and use Filecoin for most, if not all, of their
online storage needs.

3. Storage Services on Filecoin
Because Filecoinʼs economy is centered around data storage, storage miners play a central rolein the network, in both securing consensus and providing storage services. The Filecoinblockchain uses its block reward to subsidize both consensus participation and useful storage
services. This section describes how storage services are provided on the Filecoin Network,
explaining the abstractions and frameworks used to take storage that exists on different
devices in different machines and turn it into a fungible and tradable commodity in a
distributed storage network. An overview of the process of providing storage services is shownin Figure 5.

9Figure 5: Life cycle of a miner, create miners on chain, acquire tokens and commit capacity to
the network, start producing blocks when minimum miner size is reached, make deals withclients, upgrade committed capacity sectors to sectors with deals and earn additional deal
revenue, declare and recover faults.

3.1 What is a sector?
Sectors are the basic units of storage on Filecoin. They have standard sizes, as well as
well-defined time-increments for commitments, and serve as the digital storage analog to theintermodal containers in global freight shipping. The size of a sector balances security
concerns against usability. A sectorʼs lifetime is determined in the storage market, and sets thepromised duration of the sector.

10Individual deals are formed when a storage miner and client are matched on Filecoinʼs storage
market. The protocol does not distinguish miners matching with real clients from miners
generating self-deals.1 However, committed capacity is a construction that is introduced tomake self-dealing unnecessary and economically irrational.
If a sector is only partially full of deals, the network considers the remainder to be committed
capacity. Similarly, sectors with no deals are called committed capacity sectors; miners are
rewarded for proving to the network that they are pledging storage capacity and areencouraged to find clients who need storage. When a miner finds storage demand, they can
upgrade their committed capacity sectors to earn additional revenue in the form of a deal fee
from paying clients. Upgrading capacity currently involves resealing, creating a uniquerepresentation of the data through a computationally intensive process. Looking ahead,committed capacity upgrades should eventually be possible without a reseal.2
Committed capacity sectors improve minersʼ incentives to store client data, but they donʼt solve
the problem entirely. Storing real client files adds some operational overhead for storage
miners. In certain circumstances – for example, if a miner values block rewards far more thandeal fees – miners might still choose to ignore client data entirely and simply store committed
capacity to increase their storage power as rapidly as possible in pursuit of block rewards. This
would make Filecoin less useful and limit clientsʼ ability to store data on the network. Filecoin
addresses this issue by introducing the concept of verified clients. Verified clients are certified
by a decentralized network of verifiers. Once verified, they can post a predetermined amountof verified client deal data to the storage market, set by the size of their DataCap. Sectors withverified client deals are awarded more storage power – and therefore more block rewards –than sectors without. This provides storage miners with an additional incentive to store client
data.
Verification is not intended to be scarce – it will be very easy to acquire for anyone with real
data to store on Filecoin. Even though verifiers may allocate verified client DataCaps liberally(yet responsibly and transparently) to make onboarding easier, the overall effect should be a
dramatic increase in the proportion of useful data stored on Filecoin. Verified client deals aredescribed in further detail in Section 4.

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In earlier designs of the network, only sectors filled with deals increased the minerʼs likelihood of
winning the block reward. This led to the expectation that miners would attack and exploit the networkby playing the role of both storage provider and client, creating a malicious self-deal.
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A succinct and publicly verifiable proof that the committed capacity has been correctly replaced withreplicated data should achieve this goal. However, this mechanism must be fully specified to preserve
the security and incentives of the network before it can be implemented.

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Figure 6: Illustration of deal types and their impact on sector quality. Note that the sector
quality does not change during the lifetime of the sector. The sector quality is a weighted
average of deal quality multipliers of different deal types in a sector, weighted by the spacetimethat they occupy.
Given different sector contents, not all sectors have the same usefulness to the network. The
notion of Sector Quality distinguishes between sectors with heuristics indicating the presenceof valuable data. That distinction is used to allocate more subsidies to higher-quality sectors.
To quantify the contribution of a sector to the consensus power of the network, some relevant
parameters are described here.
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Sector Spacetime:​ This measurement is the sector size multiplied by its promised
duration in byte-epochs.
Deal Weight:​ This weight converts spacetime occupied by deals into consensus power.
Deal weight of verified client deals in a sector is called Verified Deal Weight and will begreater than the regular deal weight. More details in Section 6.
Deal Quality Multiplier​: This factor is assigned to different deal types (committed
capacity, regular deals, and verified client deals) to reward different content.
Sector Quality Multiplier:​ Sector quality is assigned on Activation (the epoch when theminer starts proving theyʼre storing the file). The sector quality multiplier is computed12

as an average of deal quality multipliers (committed capacity, regular deals, andverified client deals), weighted by the amount of spacetime each type of deal occupies
in the sector. Expressed algebraically,-

Raw Byte Power:​ This measurement is the size of a sector in bytes.
Quality-Adjusted Power:​ This parameter measures the consensus power of stored dataon the network, and is equal to Raw Byte Power multiplied by Sector Quality Multiplier.

The multipliers for committed capacity and regular deals are equal to make self dealing
irrational in the current configuration of the protocol. In the future, it may make sense to pickdifferent values, depending on other ways of preventing attacks becoming available.
The high quality multiplier and easy verification process for verified client deals facilitates
decentralization of miner power. Unlike other proof-of-work-based protocols, like Bitcoin,central control of the network is not simply decided based on the resources that a newparticipant can bring. In Filecoin, accumulating control either requires significantly moreresources or some amount of consent from verified clients, who must make deals with thecentralizing miners for them to increase their influence. Verified client mechanisms add alayer of social trust to a purely resource driven network. As long as the process is fair andtransparent with accountability and bounded trust, abuse can be contained and minimized. Ahigh sector quality multiplier is a very powerful leverage for clients to push storage providers
to build features that will be useful to the network as a whole and increase the networkʼslong-term value. The verification process and DataCap allocation are meant to evolve over timeas the community learns to automate and improve this process. An illustration of sectors withvarious contents and their respective sector qualities are shown in Figure 6.

3.2 Sealing Sectors
Sealing a sector through Proof-of-Replication (PoRep) is a computation-intensive process that
results in a unique encoding of the sector. Once data is sealed, storage miners: generate a
proof; run a SNARK on the proof to compress it; and finally, submit the result of thecompression to the blockchain as a certification of the storage commitment. Depending on the
PoRep algorithm and protocol security parameters, cost profiles and performance
characteristics vary and tradeoffs have to be made among sealing cost, security, onchain
footprint, retrieval latency and so on. However, sectors can be sealed with commercial
hardware and sealing cost is expected to decrease over time. The Filecoin Protocol will launchwith Stacked Depth Robust (SDR) PoRep with a planned upgrade to Narrow Stacked Expander(NSE) PoRep with improvement in both cost and retrieval latency. Figure 7 illustrates a slice ofthe tradeoff and characteristics of the two PoRep algorithms and future research direction.

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Figure 7: Illustration of cost and performance characteristics of different Proofs-of-Replication(PoReps), comparing the Stacked Depth Robust (SDR) PoReps to Narrow Stacked Expander(NSE) PoReps

3.3 Lifecycle of a Sector
Once the sector has been generated and the deal has been incorporated into the Filecoinblockchain, the storage miner begins generating Proofs-of-Spacetime (PoSt) on the sector,
starting to potentially win block rewards and also earn storage fees. Parameters are set so thatminers generate and capture more value if they guarantee that their sectors will be around forthe duration of the original contract. However, some bounds are placed on a sectorʼs lifetime
to improve the network performance. As sectors of shorter lifetime are added, the networkʼscapacity can be bottlenecked. The reason is that the chainʼs bandwidth is consumed with new
sectors only replacing expiring ones. As a result, a minimum sector lifetime of six months wasintroduced to more effectively utilize chain bandwidth and miners have the incentive tocommit to sectors of longer lifetime. The maximum sector lifetime is limited by the security ofthe present proofs construction. For a given set of proofs and parameters, the security ofFilecoinʼs Proof-of-Replication (PoRep) is expected to decrease as sector lifetimes increase. The
network plans to update the algorithm on a regular basis to improve longevity and efficiency ofthe network. Future improvements to the network will include secure proofs where sectors
have no maximum lifetime but this will not be the case for the first iteration of the protocol.

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In the first iteration of the protocol, 32GiB and 64GiB sectors are supported. Maximum sector
lifetime is determined by the proof algorithm. Maximum sector lifetime is initially 18 months.
These numbers can be adjusted with new proofs or new deal functionalities.
A sector naturally expires when it reaches the end of its lifetime. Additionally, the miner can
extend the lifetime of their sectors. Rewards are earned and collaterals recovered when theminer fulfils their commitment.
Operational risks and failures are common in storage businesses. However, it is important forstorage providers to have a strong incentive to both report the failure to the chain and attempt
recovery from the fault in order to uphold the storage guarantee for the networkʼs clients.
Without this incentive, thereʼs no way to distinguish an honest minerʼs hardware failure frommalicious behavior, which is necessary to treat miners fairly. The size of the fault fees dependon the severity of the failure and the rewards that the miner is expected to earn from the sector
to make sure incentives are aligned. The three types of sector storage fault fees are:
- Sector fault fee:​ This fee is paid per sector per day while the sector is in a faulty state.
The size of the fee is slightly more than the amount the sector is expected to earn per
day in block rewards. If a sector remains faulty for more than 2 consecutive weeks, thesector will pay a termination fee and be removed from the chain state. The initial value
for this fee is 2.14 days worth of block reward for the faulty sector. As storage miner
reliability increases above a reasonable threshold, the risk posed by these fees
decreases rapidly.
- Sector fault detection fee:​ This is a one-time fee paid in the event of a failure if theminer does not report it honestly and instead the unreported failure is caught by thechain. Given the probabilistic nature of our PoSt checks, this will be 5 daysʼ worth ofblock reward that would be expected to be earned by a particular sector.
- Sector termination fee:​ A sector can be terminated before its expiration throughautomatic faults or miner decisions. A termination fee is charged that is, in principle,
equivalent to how much a sector has earned so far, up to a limit to not discourage longsector lifetimes. In an ​active termination,​ the miner decides to stop mining and they pay
a fee to leave. In a fault termination, a sector is in a faulty state for too long (14 days),and the chain terminates the deal, returns unpaid deal fees to the client and penalizes
the miner. Termination fee is currently capped at 90 days worth of block reward that asector will earn. Miners are responsible for deciding to comply with local regulations,and may sometimes need to accept a termination fee for complying with content laws.
Many of the concepts and parameters above make use of the notion of “how much a sector
would have earned in a day” in order to understand and align incentives for participants. This
concept is robustly tracked and extrapolated on chain.
Figure 8 presents a simplified view of a sectorʼs lifecycle.

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Figure 8: Illustration of a sectorʼs lifecycle including the packing of the sector with deals, theproof-of-replication (PoRep) as part of initializing the sector, the proofs-of-spacetime (PoSts)
generated to demonstrate continued storage, and the two possible end states.

3.4 Miner Collaterals
In most permissionless blockchain networks, resources are required to participate in theconsensus. The more power an entity has on the network, the greater the share of total
resources it needs to own, both in terms of physical resources and/or staked tokens (collateral).
This ensures a capital investment at stake in the process of mining. Bitcoin and otherproof-of-work blockchains tend to pick ASICs that are hard to resell, to ensure the capital
investment is specific to the network and hard to recoup after an attack. Proof-of-stake
networks use large quantities of token stake collaterals to achieve the same function, with theadded benefit that an attacker purchasing large quantities of the token would consume token
supply, driving the price higher and thus making the attack extremely expensive.
Filecoin must also achieve security via the dedication of resources. Note that by design Filecoin
mining involves commercial hardware that is cheap in amortized cost and easy to repurpose,
which means the protocol cannot solely rely on the hardware as the capital investment at stakefor attackers. Filecoin also uses upfront token collaterals, as in proof-of-stake protocols,
proportional to the storage hardware committed. This gets the best of both worlds: attacking
the network requires both acquiring and running the hardware, but it also requires acquiring
large quantities of the token.

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To satisfy the multiple needs for collateral in a way that is minimally burdensome to miners,
Filecoin includes three different collateral mechanisms: initial pledge collateral, block reward
as collateral, and storage deal provider collateral. The first is an initial commitment of filecointhat a miner must provide with each sector. The second is a mechanism to reduce the initial
token commitment by vesting block rewards over time. The third aligns incentives between
miner and client, and can allow miners to differentiate themselves in the market. The
remainder of this subsection describes each in more detail.

3.4.1 Initial Pledge Collateral
Filecoin Miners must commit resources in order to participate in the economy; the protocol
can use the minersʼ stake in the network to ensure that rational behavior benefits the network,
rewarding the creation of value and penalizing malicious behavior via slashing. The pledge
size is meant to adequately incentivize the fulfillment of a sectorʼs promised lifetime andprovide sufficient consensus security.
Hence, the initial pledge function consists of two components: a storage pledge and aconsensus pledge. The storage pledge protects the networkʼs quality-of-service for clients byproviding starting collateral for the sector in the event of slashing. The storage pledge must be
small enough to be feasible for miners joining the network, and large enough to collateralize
storage against early faults, penalties, and fees. The vesting of block rewards and the use ofunvested rewards as additional collateral reduces initial storage pledge without compromising
the incentive alignment of the network. This is discussed in more depth in the following
subsection. A balance is achieved by using an initial storage pledge amount approximately
sufficient to cover 7 days worth of Sector fault fee and 1 Sector fault detection fee. This isdenominated in the number of days of future rewards that a sector is expected to earn.
Since the storage pledge per sector is based on the expected block reward that sector will win,
the storage pledge is independent of the networkʼs total storage. As a result, the total network
storage pledge depends solely on future block reward. Thus, while the storage pledge provides
a clean way to reason about the rationality of adding a sector, it does not provide sufficient
long-term security guarantees to the network, making consensus takeovers less costly as theblock reward decreases. As such, the second half of the initial pledge function, the consensus
pledge, depends on both the amount of quality-adjusted power (QAP) added by the sector andthe network circulating supply, which will be defined in section 6. The network targets
approximately 30% of the network's circulating supply locked up in initial consensus pledge
when it is at or above the baseline. This is achieved with a small pledge share allocated to
sectors based on their share of the networkʼs quality-adjusted power. Given an exponentiallygrowing baseline, initial pledge per unit QAP should decrease over time, as should othermining costs.

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3.4.2 Block Reward as Collateral
Clients need reliable storage. Under certain circumstances, miners might agree to a storage
deal, then want to abandon it later as a result of increased costs or other market dynamics. A
system where storage miners can freely or cheaply abandon files would drive clients awayfrom Filecoin as a result of serious data loss and low quality of service. To make sure all the
incentives are correctly aligned, Filecoin penalizes miners that fail to store files for thepromised duration. As such, high collateral could be used to incentivize good behavior andimprove the networkʼs quality of service. However, high collateral creates barriers to miners
joining the network. Filecoin must launch with a construction that satisfies both needs.
To reduce the upfront collateral that a miner needs to provide, the block reward is used ascollateral. This allows the protocol to require a smaller but still meaningful initial pledge.
Block rewards earned by a sector are subject to slashing if a sector is terminated before its
expiration. However, due to chain state limitations, the protocol is unable to do accounting ona per sector level, which would be the most fair and accurate. Instead, the chain performs a
per-miner level approximation. Sublinear vesting provides a strong guarantee that miners will
always have the incentive to complete their deals. An extreme vesting schedule would release
all tokens that a sector earns only when the sector promise is fulfilled.
However, the protocol should provide liquidity for miners to support their mining operations,and releasing rewards all at once creates supply impulses to the network. Moreover, there
should not be a disincentive for longer sector lifetime if the vesting duration also depends onlifetime of the sector. As a result, a fixed duration linear vesting for the rewards that a minerearns after a short delay creates the necessary sub-linearity. Initial parameterrecommendation puts the vesting delay at 20 days and the linear vesting duration after that fora period of 180 days.
In general, fault fees are slashed first from the soonest-to-vest unvested block rewards followedby the minerʼs account balance. When a minerʼs balance is insufficient to cover their minimum
requirements, their ability to participate in consensus, win block rewards, and grow storage
power will be restricted until their balance is restored. Overall, this reduces the initial pledge
requirement and creates a sufficient economic deterrent for faults without slashing the miner'sbalance for every penalty.

3.4.3 Storage Provider Deal Collateral
The third form of collateral is provided by the storage provider to collateralize deals. There is aminimum amount required by the protocol to provide a minimum level of guarantee, and it isslashed if the deal is terminated. However, miners can offer a higher deal collateral to imply ahigher level of service and reliability to potential clients. Given the increased stakes, clients18

may associate additional provider deal collateral beyond the minimum with an increased
likelihood that their data will be reliably stored. This collateral is returned to the storage
provider when all deals in the sector successfully conclude.

3.5 Redundancy
To enhance reliability of the storage network, the Filecoin Protocol offers storage clients
unlimited flexibility to store redundant copies of files with different miners, and to verify thatunique copies are actually being stored. Unlike centralized cloud storage services, which backup data in ways clients canʼt change or verify, Filecoin allows clients to easily express their own
preferences for reliability and cost.
Verified clients can also request that bidding miners store multiple copies of their data. Thishas the effect of the network further subsidizing redundant and reliable storage of data that arelikely to be of interest, again supporting activities that bring value to the network.

3.6 Fast retrieval
Because of the bidirectionally slow encoding currently required for a secure PoRep, theFilecoin Network can support miners additionally storing an unsealed copy of the data to
support fast retrieval of client data. Retrieval will be faster and cheaper in future PoRep
constructions. However, the early network will offer the capability for verified clients torequest that miners store an unsealed copy. The increased costs of additional storage should
be compensated by the additional block reward subsidy from the increased sector quality.
Reputation systems that will account for minersʼ adherence to these requests are underdevelopment.

3.7 Offline data transfer
Sometimes when dealing with huge troves of data, itʼs difficult (expensive andtime-consuming) to transfer those files over the internet for safekeeping. For petabyte-scale
datasets and larger, the most sensible solutions often involve shipping data on hard drives. The
Filecoin Protocol and project has tools and structures to support whatʼs known as offline datatransfers.
The two factors to consider when making the decision whether to transfer data online or off
are expense and time.
Expense:​ Using the internet to stream data, transfer costs can build very quickly.
Transferring petabytes of data in todayʼs cloud services requires sending the data
through multiple regions, incurring interconnection fees, and regional bandwidth fees,
as well as additional costs if you choose to rent a dedicated line or account for the19inevitable retries. For a rough sense of cost, the bandwidth alone to transfer 2.5
petabytes of data would cost about $140,000 – and more if youʼre moving this data acrossregions. Then, consider the cost of a hard drive itself – a physical medium to store andship the data. A server-grade 8 TiB drive costs about $200. To transfer 2.5 petabytes ofdata, for example, you would need roughly 315 hard drives, totaling approximately$63,000. While you might have slight additional per-unit costs for shipping, import fees,
and currency exchange – youʼre well below the cost of streaming the data over theinternet!
Time:​ Itʼs also time consuming to stream data. Transferring 500 TB of data at 100 Mbps
would take ​more than a year​. On the other hand, transferring the same data offline
using hard drives would take just the amount of time to download and ship – likelyyouʼd be done within a week.
Filecoinʼs offline data transfer feature allows users with very large datasets to complete thedata transfer step offline (e.g. by shipping hard drives from the client to the storage miner),and have the deal work as intended on-chain. It is implemented via a flag that tells the clientnot​ to transfer the data over the network. Instead, the client passes a piece CID (a unique
identifier describing the data), which a miner must then match for the deal to go through. This
gives the client node flexibility in how it can set up the deal – for example, passing miners a
specific location on a hard drive for the data they can use to generate the piece CID.

4. Power of a storage client
Having discussed the ways in which the Filecoin Protocol and its economy commoditize andmanage storage, itʼs important to provide additional clarity on the role of the storage clients.
They play an important role in the ecosystem, not just using the storage services, but also
shaping the storage network offering: because storage clients bring demand to anexport-oriented economy, anyone with filecoin tokens to spend on storage can push the
network to better meet consumer demand.

4.1 Client lifecycle
Equipped with data and filecoin tokens, likely obtained at an exchange, a storage client is readyto store data on the Filecoin Network. Before engaging miners, a storage client might choose
to become verified, which will be elaborated on later in this section. The client begins
participation in the storage market by preparing data into a piece, finding a miner, andproposing a deal to the miner. Once terms like price and duration are agreed upon, the minerand client enter into a deal and the client can later pay for the miner to retrieve it. Figure 9
presents an overview of clients lifecycle.

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Figure 9: Lifecycle of clients, acquire tokens, optionally become a verified client, browse miner
asks and make specific requests, make deals with miners once agreements are reached, chain
verifies storage for clients and pays miners for storage, retrieves files from miners.

4.2 Deal proposals
Deals are communicated using a gossip network, where proposals are offered by clients andminers. This free exchange of prices acts as a decentralized storage market. Many third party
entities operating on this platform can enhance the deal proposal and matching process,including participation from exchanges or the creation of novel aggregators of deal bids andasks. These communications are not even limited to one protocol or platform; storage deals
could be proposed over digital spaces like Twitter or email (especially for storing large
amounts of data), for example.

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4.3 Deals
The deals themselves are formed when storage demand and supply are met on Filecoin. In
addition to stating the storage amount, price, and duration, deals can also specify the amountof collateral that both storage miners and clients pledge during deal creation. A storage miner
would offer a provider deal collateral above the minimum amount as a differentiating factor,
allowing them to signal their commitment and level of service. Additionally, a miner could
select for deals where clients also provide collateral. This mechanism exists but is left optional
for market participants.
However, there is a minimum provider deal collateral set by the protocol, needed because thechain state and bandwidth are limited resources and providers should guarantee a minimum
level of service to clients. Minimum deal collateral requirement per unit quality adjusted
power is set such that if the network baseline is filled with deals, the sum of deal collateraltargets 5% of the circulating supply of Filecoin.
In addition to collateral commitments from both parties, thereʼs also a deal payment fromclient to miner. This payment is initially locked by the client when the deal is incorporated
into the blockchain; as a result, the clientʼs exposure to Filecoin price volatility ends themoment they enter into a storage deal. Payment is released to the miner as some fraction of thetotal deal fee per payment period. Deal payments begin to pay out immediately to provide agreater incentive for miners to seek paid client deals. If a miner terminates before a deal
expires, the miner will pay a termination fee and the provider deal collateral will be burned.
Additionally, the remaining deal payments will be returned to the client.
There is clear utility to the network from developing some additional features. To this end, thefollowing improvements are prioritized for future releases:- Deal Extension:​ A client and miner could easily agree to renew a deal.
- Deal Migration:​ Instead of implicitly bounding the maximum deal duration by thesector lifetime, a deal could be capable of outliving the sectors that contains it,
permitting it to be migrated to a new sector.
- Deal Substitution:​ A client could replace one of their deals in a sector with another fileof the same size.
- Deal Transfer​ - A miner could pass on deals to other miners with client consent.

4.4 Verified clients
As described in Section 3, verified clients as a construction make the Filecoin Economy morerobust and valuable. While a storage miner may choose to forgo deal payments and self-deal tofill their storage and earn block rewards, this is not as valuable to the economy and should not22be heavily subsidized. However, itʼs impossible in practice to tell useful data apart fromencrypted zeros. Introducing verified clients pragmatically solves this problem through social
trust and validation. There will be a simple and open verification process to become a verifiedclient; this process should attract clients who will bring real storage demand to the Filecoin
Economy.
Verifiers should eventually form a decentralized, globally distributed network of entities that
confirms the useful storage demand of verified clients. If a verifier evaluates and affirms aclientʼs demand to have real data stored, that client will be able to add up to a certain amount ofdata to the network as verified client deals; this limit is called a DataCap allocation. Verifiedclients can request an increased DataCap once they have used their full allocation and Verifiers
should perform some due diligence to ensure that the clients are not maliciously exploiting
verification. The verification process will evolve over time to become more efficient,
decentralized, and robust.
Storage demand on the network will shape the storage offering provided by miners. With theability to deploy data with a greater sector quality multiplier, verified clients play an even more
important role in shaping the quality of service, geographic distribution, degree ofdecentralization, and consensus security of the network. Verifiers and verified clients must be
cognizant of the value and responsibility that come with their role. Additionally, it isconceivable for miners to have a business development team to source valuable and usefuldataset in the world, growing demand for the storage they provide. Teams would be
incentivized to help their clients through the verification process and start storing data on the
Filecoin Network, in addition to providing their clients with strong SLAs.

5. Content delivery on Filecoin
The storage market alone is not sufficient for a functioning decentralized storage network thatcan serve as a foundation for humanityʼs information. The network must additionally provide
a mechanism by which content can be efficiently delivered to locations where it is requested.
At present, the internet achieves this distribution using a quasi-hierarchical architecture withefficient communication along the so-called backbone. Latency generally increases as thecontent and the client move farther from these high-speed connections and each other. To
facilitate efficient distribution of data, content delivery networks (CDNs) use a geographically
distributed network of servers and data centers to route requests toward the nearest copy of thedata. Moving physical copies of data is increasingly cheaper and faster than increasing
bandwidth and connectivity between servers and clients, as exemplified by ​Netflixʼs Open
Connect program​, wherein content is physically delivered to ISPs as appliances, or ​AWSʼs Snow23

Family​, which addresses the inverse problem of getting large datasets from individuals todatacenters.
Filecoin aims to provide infrastructure for a permissionless data-retrieval market. This willallow retrieval miners to bring data to the clients. Marketplace can form in different regionswith local retrieval miners serving content to local clients as illustrated in Figure 10. Market
forces inform not only how capabilities should be allocated to meet demand, but also whatcharacteristics and features are best-suited to the users needs and interests. As a result, therole this retrieval market plays is clearly distinct from the storage market, where miners
provide long term durable storage. It is also likely for storage miners to provide direct retrieval
services in the early days of the network.

Figure 10: Illustration of retrieval market on Filecoin.
A transaction on the retrieval market is outlined in Figure 11. First, a client broadcasts a query
for a specific piece of data. Retrieval miner nodes use gossipsub to spread these queries in the
network of miners. Then retrieval miners with the content return retrieval proposals, which
include price information. Clients exchange payment for data with a chosen retrieval minerusing a payment channel. To reduce the risk of malicious behavior, small amounts of data andfilecoin are exchanged incrementally. The profitability of retrieval will depend on pricing,
popularity, locality and latency

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Figure 11: Content delivery flow on Filecoin
Filecoin will launch its main network with capabilities to retrieve files, as well as the capability
for layer 2 applications to provide nascent retrieval markets and content delivery features.
Early use cases will focus on long-term storage where clients hold deals with a variety ofstorage miners. Verified clients, and the ability to request storage of a plaintext copy of the data
should improve retrieval properties.
On the day the network launches, it will include the capabilities to perform the following
actions● Address data by content hash,● Find the miner that has a specific piece of content,● Negotiate request of data by one node from another node,● Payment from client to retrieval miner in payment channel for the data retrieved.
Through improvements to the protocol, the network will support fast retrieval and short-term
access storage in the near future. More work will seed the emergence and growth of thecontent delivery market, where miners are incentivized to provide a wide range of content
delivery services. The filecoin reserve will incentivize this in the future.

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6. Demand and supply of the filecoin token
6.1 Network Baseline
Many blockchains mint tokens based on a simple exponential decay model. Under this model,
block rewards are highest in the beginning, and miner participation is often the lowest, so
mining generates many tokens per unit of work early in the networkʼs life, then rapidly
decreases.
Over many cryptoeconomic simulations, it became clear that the simple exponential decay
model would encourage short-term behavior around network launch with an unhealthy effecton the Filecoin Economy. Specifically, it would incentivize storage miners to over-invest in
hardware for the sealing stage of mining to onboard storage as quickly as possible. It would be
profitable to exit the network after exhausting these early rewards, even if it resulted in losing
client data. This would harm the network: clients would lose data and have less access tolong-term storage, and miners would have few incentives to contribute to improving the
network. Additionally, this would result in the majority of network subsidies being paid based
wholly on timing, rather than actual storage (and hence value) provided to the network.
To encourage consistent storage onboarding and investment in long-term storage, not just
rapid sealing, Filecoin introduces the concept of a network baseline. Instead of minting tokens
based purely on elapsed time, block rewards instead scale up as total storage power on the
network increases. This preserves the shape of the original exponential decay model, butsoftens it in the earliest days of the network. Once the network reaches the baseline, thecumulative block reward issued is identical to a simple exponential decay model, but if the
network does not pass the pre-established threshold, a portion of block rewards are deferred.
The overall result is that Filecoin rewards to miners more closely match the utility they, andthe network as a whole, provide to clients.
Specifically, a hybrid exponential minting mechanism is introduced with a proportion of the
reward coming from simple exponential decay, “Simple Minting” and the other proportion
from network baseline, “Baseline Minting”. The total reward per epoch will be the sum of thetwo rewards. Mining Filecoin should be even more profitable with this mechanism. Simple
minting allocation disproportionately rewards early miners and provides counter pressure to
shocks. Baseline minting allocation mints more tokens when more value for the network has
been created. More tokens are minted to facilitate greater trade when the network can unlock agreater potential. This should lead to increased creation of value for the network and lower riskof minting filecoin too quickly.

26

The protocol allocates 30% of Storage Mining Allocation in Simple Minting and the remaining
70% in Baseline Minting. 30% of Simple Minting can provide counter forces in the event ofshocks. Baseline capacity can start from a smaller percentage of worldʼs storage today, grow at
a rapid rate, and catch up to a higher but still reasonable percentage of worldʼs storage in the
future. As such, the network baseline will start from 1EiB (which is less than 0.01% of theworldʼs storage today) and grow at an annual rate of 200% (higher than the usual world storage
annual growth rate at 40%). The community can come together to slow down the rate of growthwhen the network is providing 1-10% of the worldʼs storage.
There are many features that will make passing the baseline more efficient and economical
and unleash a greater share of baseline minting. The community can come together tocollectively achieve these goals:● More performant Proof of Replication algorithms, with lower on chain footprint, fasterverification time, cheaper hardware requirement, different security assumptions,
resulting in sectors with longer lifetime and enabling sector upgrades without reseal.
● A more scalable consensus algorithm that can provide greater throughput and handle
larger volume with shorter finality.
● More deal functionalities that allow sectors to last for longer.
Lastly, it is important to note that while the block reward incentivizes participation, it cannot
be treated as a resource to be exploited. It is a common pool of subsidies that seeds and grows
the network to benefit the economy and participants. An example of different stages of theeconomy and different sources of subsidies is illustrated in Figure 12.

Figure 12: Different stages of the economy with different emphases and revenue drivers.

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6.2 Token Allocation
Filecoinʼs token distribution is broken down as follows. A maximum of 2,000,000,000 filecoin
will ever be created, referred to as FIL_BASE. Of the Filecoin genesis block allocation, 10% of
FIL_BASE were allocated for fundraising, of which 7.5% were sold in the 2017 token sale, andthe 2.5% remaining were allocated for ecosystem development, future fundraising, and/or
other uses described in 2017. 15% of FIL_BASE were allocated to Protocol Labs (including 4.5%
for the PL team & contributors), and 5% were allocated to the Filecoin Foundation. The other
70% of all tokens were allocated to miners, as mining rewards, “for providing data storage
service, maintaining the blockchain, distributing data, running contracts, and more.” There
are multiple types of mining that these rewards will support over time; therefore, thisallocation has been subdivided to cover different mining activities. A pie chart reflecting theallocations is shown in Figure 13.
Storage Mining allocation. ​At network launch, the only mining group with allocated incentives
will be storage miners. This is the earliest group of miners, and the one responsible formaintaining the core functionality of the protocol. Therefore, this group has been allocated thelargest amount of mining rewards. 55% of FIL_BASE (78.6% of mining rewards) is allocated tostorage mining. This will cover primarily block rewards, which reward maintaining theblockchain, running actor code, and subsidizing reliable and useful storage. This amount will
also cover early storage mining rewards, such as rewards in the SpaceRace competition andother potential types of storage miner initialization, such as faucets.
Mining Reserve. ​The Filecoin ecosystem must ensure incentives exist for all types of miners(e.g. retrieval miners, repair miners, and including future unknown types of miners) to
support a robust economy. In order to ensure the network can provide incentives for theseother types of miners, 15% of FIL_BASE (21.4% of mining rewards) have been set aside as a
Mining Reserve. It will be up to the community to determine in the future how to distribute
those tokens, through Filecoin improvement proposals (FIPs) or similar decentralized decision
making processes. For example, the community might decide to create rewards for retrieval
mining or other types of mining-related activities. The Filecoin Network, like all blockchain
networks and open source projects, will continue to evolve, adapt, and overcome challenges
for many years. Reserving these tokens provides future flexibility for miners and theecosystem as a whole. Other types of mining, like retrieval mining, are not yet subsidized andyet are very important to the Filecoin Economy; Arguably, those uses may need a larger
percentage of mining rewards. As years pass and the network evolves, it will be up to thecommunity to decide whether this reserve is enough, or whether to make adjustments withunmined tokens.

28

Figure 13: Filecoin token allocation.

Parameter

Value

Description

FIL_BASE

2,000,000,000 FIL

The maximum amount of FIL that will
ever be created.

FIL_MiningReserveAlloc

300,000,000 FIL

Tokens reserved for funding mining
to support growth of the Filecoin
Economy, whose future usage will bedecided by the Filecoin community.

FIL_StorageMiningAlloc

1,100,000,000 FIL

The amount of FIL allocated tostorage miners through block
rewards, network initialization, etc.

FIL_Vested

Sum of genesis MultisigActors.AmountUnlocked

Total amount of FIL that is vested
from genesis allocation.

FIL_StorageMined

RewardActor.​TotalStoragePowerReward

The amount of FIL that has been
mined by storage miners.

FIL_Locked

TotalPledgeCollateral+ TotalProviderDealCollateral+ TotalClientDealCollateral+ TotalPendingDealPayment

The amount of FIL locked as part ofmining, deals, and othermechanisms.

29

+ OtherFutureLockedFunds
FIL_CirculatingSupply

FIL_Vested+ FIL_Mined- TotalBurntFunds- FIL_Locked

The amount of FIL circulating andtradeable in the economy. The basis
for Market Cap calculations.

TotalBurntFunds

BurntFundsActor.Balance

Total FIL burned as part of penalties
and on-chain computations.

TotalPledgeCollateral

StoragePowerActor.TotalPledgeCollateral

Total FIL locked as collateral in allminers.

TotalProviderDealCollateral

StorageMarketActor.TotalProviderDealCollateral

Total FIL locked as provider deal
collateral.

TotalClientDealCollateral

StorageMarketActor.TotalClientDealCollateral

Total FIL locked as client deal
collateral.

TotalPendingDealPayment

StorageMarketActor.TotalPendingDealPayment

Total FIL locked as pending client
deal payment.

Note that exact values of parameters above are subject to changes and readers could find themost up-to-date value in the codebase.
Market Cap. ​Various communities estimate the size of cryptocurrency and token networks
using different analogous measures of market capitalization. The most sensible token supply
for such calculations is ​FIL_CirculatingSupply,​ because unmined, unvested, locked, and burnt
funds are not circulating or tradeable in the economy. Any calculations using larger measures
such as FIL_BASE are likely to be erroneously inflated and not to be believed.
TotalBurntFunds. ​Some filecoin are burned to fund on-chain computations and bandwidth as
network transaction fees, in addition to those burned in penalties for storage faults andconsensus faults, creating long-term deflationary pressure on the token. Accompanying the
network transaction fees is the priority fee that is not burned, but goes to the block-producing
miners for including a transaction.

7. Initial parameter recommendation
Economic analyses and models were developed​ to design, validate, and parameterize themechanisms described in the previous sections. Cryptoeconomics is a young field, where
global expertise is both sparse and shallow. As such, designing mechanisms like this requires alevel of intellectual depth typical of scientific research, in conjunction with a scale of“engineering in the large” typical of aerospace. Developing these recommendations is30

advancing the state of the art, not only of decentralized storage networks, but also of
cryptoeconomic mechanism design as a whole discipline. A lot of advances have been madebut this work continues. The following table summarizes initial parameter recommendations.
These will continue to evolve and adapt through testing and validation during incentivized
testnet, leading up to Mainnet launch and beyond.
Parameter

Value

Baseline initial value

1 EiB

Baseline annual growth rate

200%

Percent simple minting vs baseline minting

30%/70%

Reward delay and linear vesting period

20 days and 180 days

Sector quality multipliers

Committed Capacity: 1x
Regular Deals: 1x
Verified Client Deals: 10x

Initial pledge function

20 days worth of block reward + share of 30%
FIL circulating supply target

Minimum sector lifetime

180 days

Maximum sector lifetime

540 days

Minimum deal duration

180 days

Maximum deal duration

540 days

Sector fault fee

2.14 days worth of estimated block reward

Sector fault detection fee

5.00 days worth of estimated block reward

Sector termination fee

Estimated number of days of block rewardthat a sector has earned; capped at 90 days

Network transaction fee

Dynamic fee structure based on network
congestion

Why have baseline minting?​ Filecoin tokens are a limited resource. The rate at which tokens
are deployed into the network should be controlled to maximize their net benefit to thecommunity, just like the consumption of any exhaustible common-pool resource. The
purposes of baseline minting are (a) to reward participants more proportionately for the31storage they provide rather than exponentially more based on the time when they join the
network, (b) and to adjust minting rate based on approximated network utility to maintain arelatively steady flow of block rewards for longer.
Why have an initial pledge?​ First, an initial pledge gives storage miners something to lose if
they renege on their sector commitments, even before they have earned any block rewards.
Second, requiring a pledge of stake in the network supports the security of the consensus
mechanism.
Why have block-reward vesting?​ To reduce the initial pledge requirement of a sector, thenetwork considers all vesting block rewards as collateral. However, tracking block rewards on
a per-sector level is not scalable. Instead, the protocol tracks rewards at a per-miner level andlinearly vests block rewards over a fixed duration.
Why have a minimum sector lifetime? ​Committing a sector to the Filecoin Network currently
requires a moderately computationally-expensive “sealing” operation up-front, whose
amortized cost is lower if the sectorʼs lifetime is longer. In addition, a sector commitment will
involve on-chain transactions, for which gas fees will be paid. The net effect of thesetransaction costs will be subsidized by the block reward, but only for sectors that willcontribute to the network and earn rewards for a sufficiently long duration. Under current
constraints, short-lived sectors would reduce the overall capacity of the network to deliveruseful storage over time.
Why have a sector fault fee?​ If stored sectors are withdrawn from the network only
temporarily, a substantial fraction of those sectorsʼ value may be recovered in case the data
storage is quickly restored to normal operation—so the network need not levy a termination fee
immediately. However, even temporary interruptions can be disruptive, and also damage
confidence about whether the sector is recoverable or permanently lost. So the network
charges a much smaller fee per day that a sector is not being proven as promised (until enoughdays have passed that the network writes off that sector as terminated).
Why have a sector fault detection fee?​ If a sector is temporarily damaged, storage miners are
expected to proactively detect, report, and repair the fault. An unannounced interruption inservice is both more disruptive for clients and more of a signal that the fault may not have beencaught early enough to fully recover. Finally, dishonest storage miners may have some chanceof briefly evading detection and earning rewards despite being out of service. For all thesereasons, a higher penalty is assessed when the network detects an undeclared fault.
Why have a sector termination fee?​ The ultimate goal of the Filecoin Network is to provide
useful data storage. Use-cases for ​unreliable​ data storage, which may vanish without warning,32

are much rarer than use-cases for ​reliable d​ ata storage, which is guaranteed in advance to be
maintained for a given duration. So to the extent that committed sectors disappear from the
network, most of the value provided by those sectors is canceled out, in most cases. If storage
miners had little to lose by terminating active sectors compared to their realized gains, thenthis would be a negative externality that fails to be effectively managed by the storage market;
termination fees internalize this cost.

8. Growth and governance of the Filecoin Network
8.1 Upcoming features
The functionality and performance of the Filecoin Network will evolve over time. The
following are examples of such growth.
●

●

●

●
●
●

Repair Miners:​ Currently, if a miner stops storing a sector, they pay a termination fee
as described above. However, if another miner is storing the data, there should be an
actor, referred to as a repair miner, who retrieves the data and sets up a new deal on
behalf of the original client, integrating the data into a new sector and ensuring that astable number of replicas are stored.
App Miners:​ A significant fraction of the value of storage services comes fromapplications, improved user experience, and differentiated use cases that are developedon the service itself. Hence, it is important for a future version of Filecoin to incentivize
the development of high-quality applications that utilize the market.
Filecoin Loans:​ Token holders should be able to use their tokens as deployed capital forminers as third party collateral, sharing the volatility risks and earning a yield inpartnership with the miners.
Fast Retrieval PoRep: ​Future proofs-of-replication will provide natively secure, fast,and efficient retrieval.
Scalable Consensus: ​Improved consensus mechanisms will lead to improved
throughput and security.
Generalized Smart Contracts: ​Future improvements to the Filecoin blockchain willallow the use of generalized smart contracts and an on-chain state machine.

These improvements will make Filecoinʼs economy significantly more productive. This
increased productivity may lead to demand and the largest long-term growth and robustness,increasing the networkʼs utility.

33

8.2 Governance and improvementItʼs important to have a process and mechanism to collectively decide on the future of the
network after Mainnet launch. The Filecoin Network will use a Filecoin improvement proposal(FIP) practice similar to Bitcoinʼs BIPs and Ethereumʼs EIPs. The FIP process details have notyet been finalized, but all updating of parameters and mechanisms after the Filecoin Mainnet
launch will be determined using FIPs.
In closing, itʼs important to reiterate that Filecoin will be a collaboratively constructedeconomy that will evolve over time. However, improvements will be clearly explained as
proposals that further the long-term interests of Filecoinʼs Economy and each category of its
participants. As the network grows, using limited tools and subsidies to build a robust
economy that can function independently and without subsidies is of paramount importance.

34