虛擬貨幣購物問題 - 數位貨幣

我還是直接回文好了，中本聰當初的比特幣架構本來就是Distributed client-sever架構

才不是Core宣稱的直接的P2P架構

不然白皮書也沒必要去寫第七節和第八節，大家都完整節點不就解決了嗎?

http://satoshinakamoto.me/zh-tw/bitcoin.pdf

但是中本聰的雄心壯志是全球就一個區塊鏈，一個新一代的金流網際網路

https://bitcointalk.org/index.php?topic=149668.msg1596879#msg1596879

比特幣必須能達到VISA規模的處理能力

以下節錄自中本聰2009年的信件，有些部分我就大致翻一下

There is only one global chain.

全世界只會有一條區塊鏈

The existing Visa credit card network processes about 15 million Internet
purchases per day worldwide. Bitcoin can already scale much larger than that
with existing hardware for a fraction of the cost. It never really hits a
scale ceiling. If you're interested, I can go over the ways it would cope
with extreme size.

現在的VISA卡每天處理全球一千五百萬的網路交易

比特幣將可以用現有硬體擴容到比現有VISA卡更大的處理能力

但卻只有VISA卡交易系統一部分的成本

它將永遠不會碰到擴容瓶頸，陳述如下:

By Moore's Law, we can expect hardware speed to be 10 times faster in 5 years
and 100 times faster in 10. Even if Bitcoin grows at crazy adoption rates, I
think computer speeds will stay ahead of the number of transactions.

依照摩爾定律，我們可以預期在五年內，

硬體將會比現在快五到十倍，在十年內將會快一百倍，

比特幣應用就算是高速成長，我仍然預期電腦的速度會比交易成長的速度快。

I don't anticipate that fees will be needed anytime soon, but if it becomes
too burdensome to run a node, it is possible to run a node that only
processes transactions that include a transaction fee. The owner of the node
would decide the minimum fee they'll accept. Right now, such a node would
get nothing, because nobody includes a fee, but if enough nodes did that,
then users would get faster acceptance if they include a fee, or slower if
they don't. The fee the market would settle on should be minimal. If a node
requires a higher fee, that node would be passing up all transactions with
lower fees. It could do more volume and probably make more money by
processing as many paying transactions as it can. The transition is not
controlled by some human in charge of the system though, just individuals
reacting on their own to market forces.

我不預期比特幣交易在短時間會需要手續費(的確在早期比特幣傳輸是零手續費)，

但是假如運作完整節點需要大量資源，那麼完整節點將只會包含有手續費的交易

完整節點的運作者可以決定進到區塊的最低手續費。

在現在，運行完整節點收不到手續費(2009年)，因為沒有人會付手續費，

但假如有足夠多的節點需要手續費，那麼使用者為了快點被確認，會需要付手續費

但就算如此，因為競爭的壓力，手續費仍然會壓到最便宜。

這不是由某些人決定的，而是市場機制決定

Eventually, most nodes may be run by specialists with multiple GPU cards.
For now, it's nice that anyone with a PC can play without worrying about
what video card they have, and hopefully it'll stay that way for a while.
More computers are shipping with fairly decent GPUs these days, so maybe
later we'll transition to that.

最後，大多數的完整節點會由專業礦工使用GPU來挖礦
(中本聰有預期到挖礦專業化，但是沒有預期到ASIC這麼快就跑出來)

後來中本聰提到了擴容和SPV安全性的問題

https://bitcointalk.org/index.php?topic=286.msg2947#msg2947

The design outlines a lightweight client that does not need the full block
chain. In the design PDF it's called Simplified Payment Verification. The
lightweight client can send and receive transactions, it just can't generate
blocks. It does not need to trust a node to verify payments, it can still
verify them itself.

輕錢包不需要下載完整的區塊鏈，我已經寫在白皮書裡啦，叫做簡化支付驗證。

輕錢包client端可以傳送和接收交易，它只是無法產生區塊而已。

它也不需要一個可信的節點去驗證交易

它可以靠它自己去驗證交易的有效性(地址、公鑰、簽章對一下不就知道?)

The lightweight client is not implemented yet, but the plan is to implement
it when it's needed. For now, everyone just runs a full network node.

在2010年輕錢包還沒被實作出來，在2010年，要使用比特幣，必須跑完整節點。

I anticipate there will never be more than 100K nodes, probably less. It
will reach an equilibrium where it's not worth it for more nodes to join in.
The rest will be lightweight clients, which could be millions.

我可以預期到永遠都不會有超過十萬個完整節點，甚至是更少的

它會達到一個動態平衡，因為不需要更多啦

剩下的人會去運作輕錢包，那可能是上百萬人

At equilibrium size, many nodes will be server farms with one or two network
nodes that feed the rest of the farm over a LAN.

在這平衡狀態的規模，許多節點會是機房，數個網路節點直接透過LAN相連

哇靠，嚇到我吃手手了

中本聰竟然支持中心化


我全都用中本聰的話來說囉，中本聰的第一目標是要實現一個全球的金流網際網路。

它必須要達到VISA規模的處理能力，所以必定無法使用純粹P2P方式的架構。

所以他才設計了一個distributed client-server架構的比特幣網路

server就是這些中心化的礦工，他們運行完整錢包，又或者是支付處理商。

而這些中心化的礦工擁有大量的運算和儲存資源，並用專線相連。

所以其實中本聰根本不在意區塊會有多大，

最早期版本的比特幣根本沒有區塊大小的限制，連白皮書都沒有提到

client就是一般使用者，運行SPV錢包，而這已經足夠be your own bank

他們只需要確保自己交易的安全，所以會非常省運算和儲存資源。


這也就是為什麼早期bitcoin開發者敢列出以下的擴容roadmap

http://i.imgur.com/VIGwE80.gif

因為這些頻寬和儲存成本都是由中心專業化的礦工在負擔，他們負擔不起就不要賺錢啊

就這麼簡單啊~~~

為了賺錢連ASIC都研發的出來了，遠超乎中本聰的預期。

結果你跟我講說這些專業化礦工負擔不起頻寬和儲存成本??

實際上隨便一間稍有規模的網路公司機房都絕對可以負擔區塊擴容到100MB的成本

真有那麼貴，一大堆網路影音公司早就倒光了。

不過現在說這些都沒用了，中本聰當初的理想已經徹底被blockstream毀滅

我現在反而比較期待blockstream的閃電網路到底什麼時候才要出來玩XD

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