DAICO就是ICO的升級版，融合了DAO的一些方面。
Facepay於2018年1月提出了DAICO的想法，意圖在項目開發初始階段引入投資人，以此提升ICO安全性。
通證持有人若對項目進展不滿意，可以通過投票決議退款。
DAICO的概念，一來向開發者施加了一定的問責，二來通證持有人要麼能看到至少是可行的產品，要麼能退款，心裡多少踏實些。
# DAICO原理
DAICO始於智能合約的捐獻功能。
DAICO合約中允許捐獻人向項目發送資金換取網絡通證。眾籌結束後，合約禁止任何捐獻行為，也就是正常的通證銷售。
眾籌結束，合約中的一個變量開始生效，叫tap變量，對tap編程後，可以預設開發者從通證銷售收入中支取資金的數量，或者說流量（金額/每秒計）。tap變量可以理解水龍頭，是控制合約中資金釋放的一道閥門。
Tap長這樣：
tap: num(wei / sec)
lastWithdrawn: timestamp # Make sure to initialize this to thecontribution period end time
@public
def withdraw():
send(self.owner, (block.timestamp - self.lastWithdrawn) * self.tap)
self.lastWithdrawn = block.timestamp
@private
def modify_tap(new_tap: num(wei / sec)):
self.withdraw()
self.tap = new_tap
開發者可支取資金數量的初始設定為0，由捐獻人投票表決tap上限變更。
# 水龍頭機制（Tap Mechanism）
上面提到，DAICO融入了DAO的一些特徵，有三個主要方面：
首先，不完全信任某中心團隊。有關資金的一系列決策從一開始就由民眾投票決定。
其次，資金非一次性發放，水龍頭機制專門用來“緩釋”資金。
最後，允許退款的可能。有鑑於退款依靠投票結果，好比，若項目無法落地，捐獻人可以投票決定退還剩餘資金。
注：
1.
無法通過投票降低 tap 上限。
2.
3.
允許開發者自願降低 tap上限，但無法單方面提高tap上限。
4.
# 與ICO的區別
主要區別在於資金的獲取程度。
ICO中，通證銷售完畢，開發者即可擁有對全部資金的獲取權。開發者需要計算開發出最低可用產品的成本，也叫軟上限。達到此上限，資金可被用到產品開發或其他開發者認為有必要的地方。若不到軟上限，需退還資金。過了上限之後，開發基本就靠自律了。
DAICO中，允許捐獻者在開發階段投票決議，比方說提高tap上限或使用自毀合約退還剩餘資金（確切是說是合約的提現模式，將剩餘的ETH按比例退換通證持有人）。
# DAICO優勢
投資人的主人翁精神更濃。
捐獻人在項目開發期間的話語權更多，影響力也更強。再不濟，至少可以撤銷合約，獲得退款。
這樣一來，能夠規避些捲款跑路（更別說產品了）的風險。
因為智能合約釋放的資金數量有限且受到嚴格控制，也能降低可能出現51的%攻擊，即攻擊者將資金髮送至指定第三方。即便真發生了，被捲走的資金也是捐獻人授權釋放的數額。
•
發動51%攻擊提高 tap 上限– 良心開發者可以自發降低 tap，或者不提現剩餘資金。
•
•
51%攻擊以自毀合約 - 良心開發者可以另發佈個 DAICO。
•
另外，ICO中，開發團隊募集大筆資金後，項目實施的積極性明顯降低。那麼DAICO模型中，開發團隊的緊迫感至少是被吊住的，時刻保持推出產品是使命感。
# DAICO面臨的挑戰
任何新概念都有一定的挑戰需要應對，DAICO也不例外。
比方說，若開發團隊掌握大量通證，只需影響少量捐獻人即可左右投票結果，釋放合約中更多的資金。
捐獻人科普也很重要，好比知道通證漲跌的原因，方便tap上限投票亦或是退款時，能夠做出合理的判斷。要知道決策最好基於對項目情況的掌握，而非單純由通證價格漲跌造成的情緒波動。
最後，捐獻人對DAICO的完全信任，也同時將自身抽離。感覺起來就是有人替自己處理這些，沒必要什麼事情（投票決議）都親力親為。如此，降低了大眾門檻的同時，降低了機制的安全性。
# DAICO的主要特徵
我們參考下其他項目計劃採用DAICO設計的相應規則：
•
提高tap上限的投票只能由項目開發者發起。
•
•
單次tap上限提高有百分比限制，用來防止資金揮霍。
•
•
提高tap上限頻次有限制，好比，每兩週一次。
•
•
僅投資人持有的通證有投票效力，開發者持有的通證不能投票。
•
•
民調前，捐獻人妥善通知。
•
•
捐獻人決定終止項目時，智能合約改為提款並返還資金，同時銷燬開發者手中的通證。
Facepay在2019年6月進行DAICO
What is DAICO?
DAICO is an upgraded version of ICO that combines aspects of DAO.
Facepay proposed DAICO in January 2018 with the intention of introducing investors in the initial stages of project development to improve ICO security.
If the holder of the certificate is dissatisfied with the progress of the project, he can vote to vote for a refund.
The concept of DAICO has given the developer a certain degree of accountability. Secondly, the holder of the certificate can either see at least a viable product, or refund it, and be more practical.
# DAICO principle
DAICO began with the donation function of smart contracts.
The DAICO contract allows donors to send funds to the project in exchange for a network pass. After the end of crowdfunding, the contract prohibits any donation, which is normal pass sales.
At the end of crowdfunding, a variable in the contract comes into effect, called the tap variable. After programming the tap, you can preset the amount of funds that the developer can withdraw from the license sales revenue, or the amount of traffic (amount/per second). The tap variable understands the tap and is a valve that controls the release of funds in the contract.
Tap is like this:
Tap: num(wei / sec)
LastWithdrawn: timestamp # Make sure to initialize this to the contribution period end time
@public
Def withdraw():
Send(self.owner, (block.timestamp - self.lastWithdrawn) * self.tap)
self.lastWithdrawn = block.timestamp
@private
Def modify_tap(new_tap: num(wei / sec)):
Self.withdraw()
Self.tap = new_tap
The initial setting of the amount of funds that the developer can withdraw is 0, and the donor limits the change of the tap cap.
#Tap Mechanism
As mentioned above, DAICO incorporates some of the features of DAO and has three main aspects:
First, don't fully trust a central team. A series of decisions about funds were decided by the popular vote from the beginning.
Secondly, the funds are not issued at one time, and the faucet mechanism is specially used to “slow release” funds.
Finally, the possibility of a refund is allowed. In view of the fact that the refund depends on the voting result, for example, if the project cannot be settled, the donor can vote to return the remaining funds.
Note:
1.
Unable to lower tap limit by voting.
2.
3.
Allow developers to voluntarily lower the tap limit, but not unilaterally increase the tap limit.
4.
# Difference from ICO
The main difference is the degree of access to funds.
In the ICO, when the license is sold, the developer can have access to all funds. Developers need to calculate the cost of developing the lowest available product, also known as the soft cap. To reach this limit, funds can be used for product development or where other developers deem it necessary. If the soft limit is not reached, the funds will be refunded. After the upper limit, development is basically self-disciplined.
In DAICO, donors are allowed to vote in the development stage, for example, to increase the tap limit or to use the self-destruction contract to return the remaining funds (exactly, the withdrawal mode of the contract, the remaining ETH is proportionally returned to the holder).
# DAICO advantage
The ownership of the investor is stronger.
Donors have more voice and influence during project development. If you are not good enough, you can at least cancel the contract and get a refund.
In this way, you can avoid the risk of running some money (not to mention the product).
Because the amount of money released by smart contracts is limited and tightly controlled, it can also reduce the percentage of attacks that may occur by 51, that is, the attacker sends funds to a designated third party. Even if it does happen, the money that was taken away is the amount that the donor authorized to release.
•
Launch a 51% attack to increase the tap cap – Conscience developers can reduce taps spontaneously or not withdraw the remaining funds.
•
•
51% attack with self-destruction contract - Conscience developers can release another DAICO.
•
In addition, in the ICO, after the development team raised a large amount of funds, the enthusiasm of the project implementation was significantly reduced. Then, in the DAICO model, the urgency of the development team is at least hanged, and it is a sense of mission to keep the product launched at all times.
# DAICO challenges
Any new concept has certain challenges to deal with, and DAICO is no exception.
For example, if the development team has a large number of passes, only a small number of donors can influence the voting results and release more funds in the contract.
Donor science is also very important, just like knowing the reasons for the ups and downs of the pass, and it is convenient to make a reasonable judgment when it is convenient to vote or to refund. It is important to know that decision-making is best based on mastery of the project, rather than simply emotional fluctuations caused by the price of the pass.
Finally, the donor’s full trust in DAICO also draws itself away. It feels like someone is dealing with this for themselves, and there is no need to do anything (voting resolutions). In this way, the public threshold is lowered and the safety of the mechanism is reduced.
# DAICO's main features
We refer to the corresponding rules of other projects planned to adopt DAICO design:
•
Voting to increase the tap limit can only be initiated by the project developer.
•
•
A single tap increase has a percentage limit to prevent money from being squandered.
•
•
There is a limit to increasing the frequency of tap caps, for example, every two weeks.
•
•
Only the certificate held by the investor has the effect of voting, and the certificate held by the developer cannot vote.
•
•
Donors are properly notified before the polls.
•
•
When the donor decides to terminate the project, the smart contract is changed to withdraw the money and return the funds, while destroying the certificate in the hands of the developer.
Facepay conducted DAICO in June 2019
•
閱讀更多 數字貨幣未來 的文章
