- BLS 签名的首次生产使用。
奇亚的主网于 2021 年 3 月 19 日启动。其生态系统的开发正在进行中。
Chia is a cryptocurrency and blockchain smart transaction platform. Chia was designed from the ground up to make cryptocurrency easier to use -- and harder to lose -- than cash. Chia's blockchain maintains the same level of security as Bitcoin's, while using a fraction of the energy.
On August 1, 2017, Bram Cohen founded the Chia company and incorporated it in the state of Delaware. Bram led the development of Chia, along with many engineers, researchers, and open source contributors. Along the way, Chia created three new inventions in applied cryptography, and advanced the interest and adoption in a fourth:
- The first production use of BLS Signatures.
- The first production use of a Verifiable Delay Function (VDF).
- Proofs of Space and Time (PoST), the first (and only) Nakamoto consensus since Proof of Work.
- The first production use of class groups of unknown order.
Chia's mainnet was launched on March 19, 2021. Development of its ecosystem is ongoing.
For more information on the company's strategies, see Chia's business white paper.
奇亚有一个新的智能交易模型，它使用一个强大（但简单）的高级语言 chialisp，以及一个伴随的低级语言 CLVM (Chialisp 虚拟机）。
奇亚使用硬币集合模型（类似于比特币的 UTXO）来跟踪区块链的状态。该模型的简单性质有助于编写高价值和安全的合同。与使用帐户模型的系统（例如以太坊）不同，创建奇亚代币的代码被严格沙盒化，这提高了安全性，降低了最大可提取价值 (MEV)，并使代码完全可审计。
有关奇亚智能交易的更多信息，请参阅第 4.1 节。
coinID = sha256(parent_ID + puzzlehash + amount)
硬币的 ID（sha256 哈希）是存储在区块链上的主要内容。 由于哈希是不可逆的，所以分析区块链的黑客甚至很难确定硬币的类型，更不用说查看创建它的代码了。与以太坊相比，使用反编译器查看智能合约的源代码是微不足道的。
同样由于哈希（的不可逆性），黑客不能在不更改 ID 的情况下更改硬币的谜语 ID、谜语哈希或金额。黑客可以尝试更改硬币的唯一方法是更改它的谜底，确保任何此类更改都将导致花费失败是微不足道的。
与工作量证明 (PoW) 相比，PoST（时空证明）共识具有更低的能耗，并且奇亚的部分愿景是改善区块链行业的碳足迹。
奇亚的共识算法在第 3 节中有详细讨论。
当赢得一个区块时，农民获得 1/8 的奖励，矿池运营商获得另外的 7/8。这样做是为了阻止当矿池运营商在竞争矿池中耕种，获得证明时却忽略创建区块，从而损害他们的竞争。（作为个体的农民在创建区块时会获得全部奖励。）
有关奇亚矿池协议的更多信息，请参阅第 11 节。
- BLS 签名，允许将一个区块的所有签名聚合在一起。
- 权重证明和轻量客户端，可从移动设备快速同步。更多详细信息，请参阅第 3.12 节。
Chia aims to improve upon Bitcoin's many pioneering ideas in the fields of cryptography and digital currencies, while maintaining the same overall purpose and philosophy. Some of Chia's new features and improvements include:
Chia has a new smart transaction model, which uses a powerful (yet simple) higher-level language called chialisp, and an accompanying lower-level language called CLVM (ChiaLisp Virtual Machine).
Chia uses the coin set model (similar to Bitcoin's UTXO) to track the blockchain's state. The simple nature of this model facilitates the writing of high value and secure contracts. Unlike in systems that use the account model such as Ethereum, the code that creates Chia's coins is strongly sandboxed. This increases security, reduces Maximum Extractable Value (MEV), and makes the code fully auditable.
For more info on Chia's smart transactions, see Section 4.1.
Chia's coins are created in a simple, yet highly secure manner:
coinID = sha256(parent_ID + puzzlehash + amount)
The coin's ID (a sha256 hash) is the main aspect that's stored on the blockchain. Hashes are not reversible, so it's very difficult for a hacker analyzing the blockchain to even determine what a coin's type is, let alone to view the code that created it. Contrast that with Ethereum, where it's trivial to view a smart contract's source code by using a decompiler.
Also due to hashing, a hacker cannot change a coin's parent_ID, puzzlehash, or amount without changing the ID as well. The only aspect of a coin that a hacker can attempt to change is its solution, and it's trivial to ensure that any such changes will result in a failure to spend the coin.
For more info, see chialisp.com.
The PoST consensus has a much lower energy consumption compared to Proof of Work (PoW), and part of Chia's vision involves improving the carbon footprint of the blockchain industry.
Chia's consensus algorithm is discussed in detail in Section 3.
Chia uses a consensus algorithm called Proofs of Space and Time. This algorithm allows anyone with an internet connection and some free disk space to participate in securing the network. Because of this process of farming (analogous to mining), Chia has become the most decentralized blockchain on the planet, with hundreds of thousands of full nodes securing the system.
Like many other blockchains, Chia allows pooling to smooth out the rewards structure for smaller farmers. However, Chia's pooling protocol has three unique features:
Farmers create new blocks, whether they're farming solo or as a member of a pool.
This design decision was made in conjunction with Chia's goal of decentralization. In other blockchains such as Bitcoin, four or five pools control over 51% of the global hashrate on any given day. (Sources: blockchain.com, blockchair.com) Arguably, the easiest way to attack Bitcoin would be to bribe each of these pools' operators.
In Chia, the pool operators are only responsible for distributing rewards. They cannot modify the blockchain. Therefore, Chia's pooling protocol doesn't lead to increased centralization.
Joining a pool is permissionless. Farmers don't need to sign up for anything in order to join.
When a block is won, the farmer gets 1/8 of the rewards, and the pool operator gets the other 7/8. This was done to discourage pool operators from harming their competition by farming on a competing pool and neglecting to create a block when they find a proof. (Solo farmers collect the entire reward when they create a block.)
For more info on Chia's pooling protocol, see Section 11.
There are many other innovations in Chia, some of which include:
- BLS signatures, which allow aggregating all of a block's signatures together.
- Scalability and performance improvements, which allow running a Chia node on a Raspberry Pi.
- Weight proofs and light clients, which enable fast syncing from a mobile device. For more info, see Section 3.12 .
This documentation will explain the motivation and implementation of the different components of the Chia system to a technical audience, and provide in-depth explanations of how everything works. If you would like to skip to how to make dapps (decentralized apps) on Chia, please visit chialisp.com.