Does digital ID have risks even if it's ZK-wrapped?

Special thanks to Balvi volunteers, Silviculture members and World team members for discussion.

特别感谢 Balvi 志愿者、Silviculture 成员和 World 团队成员的讨论。

The use of zero-knowledge proofs to protect privacy in digital ID systems is now becoming at least somewhat mainstream.

使用零知识证明来保护数字身份系统中的隐私现在至少在某种程度上已成为主流。

Various ZK-passport projects are creating very user-friendly software packages that use zero-knowledge proofs to prove that a user has a valid ID without revealing any details of their ID.

各种 ZK-passport 项目正在创建非常用户友好的软件包，这些软件包使用零知识证明来证明用户拥有有效的 ID，而无需透露其 ID 的任何详细信息。

World ID (formerly Worldcoin), which uses biometrics for verification and zero knowledge proofs for privacy, recently passed 10 million users .

使用生物识别技术进行验证和隐私零知识证明的 World ID（原 Worldcoin）最近拥有超过 1000 万用户。

A Taiwan government project for digital ID uses zero knowledge proofs, and EU digital ID work is also increasingly taking zero knowledge proofs seriously .

台湾政府的数字ID项目使用了零知识证明，欧盟的数字ID工作也越来越重视零知识证明。

On the surface, widespread adoption of ZK-wrapped digital ID seems like it would be a great victory for d/acc , protecting our social media, voting, and all kinds of internet services against manipulation from sybils and bots, all without compromising on privacy.

从表面上看，ZK 包装的数字 ID 的广泛采用似乎对 d/acc 来说是一个伟大的胜利，保护我们的社交媒体、投票和各种互联网服务免受女巫和机器人的操纵，所有这些都不会损害隐私。

But is it that simple, or does ZK-wrapped ID still have risks?

但真有这么简单吗，还是ZK包裹的ID仍然存在风险呢？

This post will make the following argument:

这篇文章将提出以下论点：

Imagine that you've scanned your eyeballs to get a World ID.

想象一下，您已经扫描了眼球以获得世界 ID。

Or perhaps, you scanned your passport with your phone's NFC reader to get a ZK-passport-based ID.

或者，您可能使用手机的 NFC 读取器扫描您的护照，以获得基于 ZK 护照的 ID。

For the purposes of the arguments made in this post, the two have the same properties (barring a few edge cases like multiple citizenships).

就本文中提出的论点而言，两者具有相同的属性（除了一些边缘情况，例如多重公民身份）。

On your phone, you have a secret value, s .

在您的手机上，您有一个秘密值 s 。

In the onchain global registry, there is a public hash, H(s) .

在链上全局注册表中，有一个公共哈希值 H(s) 。

To log into an application, you generate an application-specific user ID, H(s, app_name) , and you use a zero-knowledge proof to prove that this ID comes from the same s as one of the public hashes in the registry.

要登录应用程序，您需要生成一个特定于应用程序的用户 ID H(s, app_name) ，并使用零知识证明来证明该 ID 与注册表中的公共哈希值之一来自相同的 s 。

Hence, for each public hash, you can only generate one ID for each application, but it is never revealed which application-specific ID corresponds to which public hash.

因此，对于每个公共哈希，您只能为每个应用程序生成一个 ID，但永远不会透露哪个特定于应用程序的 ID 对应于哪个公共哈希。

In reality, the design can be somewhat more complex.

实际上，设计可能会更复杂一些。

In World ID, the app-specific ID is actually a hash that takes in the application ID and a session ID .

在 World ID 中，应用程序特定的 ID 实际上是一个包含应用程序 ID 和会话 ID 的哈希值。

Hence, different actions within the same app can also be unlinked from each other.

因此，同一应用程序中的不同操作也可以相互取消链接。

A ZK-passport-based design can be built in a similar way.

基于 ZK-passport 的设计可以用类似的方式构建。

Before we get into the downsides of this type of identity, it's first important to appreciate the upsides that it offers.

在我们了解这种身份的缺点之前，首先要认识到它所提供的优点。

Outside of the very small world of ZKID, in order to authenticate yourself to a service that requires ID, you need to actually reveal your legal identity.

在 ZKID 的小世界之外，为了向需要 ID 的服务验证您的身份，您需要实际透露您的合法身份。

This is a gross violation of the common computer-security principle of least privilege : a process should only get the least authority and information required to accomplish its task.

这严重违反了常见的计算机安全最小特权原则：进程应该只获得完成其任务所需的最少权限和信息。

They need a proof that you're not a bot, or are over 18, or are from a particular country; they get a pointer to your entire identity.

他们需要证明您不是机器人、或已年满 18 岁、或来自特定国家/地区；他们会获得指向您整个身份的指针。

The best that we get as an improvement is indirect tokens like phone numbers or credit card numbers, where the actor knowing the link between your phone or credit card number and your activity (the app), and the actor knowing the link between your phone or credit card number and your legal identity (the company or bank) are separate.

我们得到的最好的改进是间接标记，例如电话号码或信用卡号码，其中知道您的电话或信用卡号码与您的活动（应用程序）之间的链接的行为者，以及知道您的电话或信用卡号码与您的合法身份（公司或银行）之间的链接的行为者是分开的。

But even this separation is very tenuous: phone numbers get leaked all the time , as does everything else.

但即使这种分离也是非常脆弱的：电话号码总是会被泄露，其他一切也是如此。

With ZK-wrapping, these problems to a large extent go away .

通过 ZK-wrapping，这些问题在很大程度上消失了。

Now, let's get to what has so far been less discussed: the remaining problems that do not go away, and in fact may even get worse specifically because of the stronger one-per-person restriction of these schemes.

现在，让我们来看看迄今为止讨论较少的问题：剩下的问题不会消失，事实上，由于这些计划对每人一人的限制更加严格，这些问题甚至可能变得更糟。

Suppose that a ZK-identity platform works exactly as intended, faithfully replicating all the logic above, and we even figure out how to keep user secrets safe for the long term, for non-technically-proficient users, without trusting centralized authorities.

假设 ZK 身份平台完全按照预期工作，忠实地复制上述所有逻辑，我们甚至弄清楚如何为非技术熟练的用户长期保证用户秘密的安全，而无需信任中心化机构。

But at the same time, let us make the realistic assumption that applications will not be cooperative; they will be "pragmatic", pursuing design choices that are justified as maximizing user convenience but that always seem to lean toward their political and business interests.

但同时，让我们做出现实的假设：应用程序不会合作；他们将是“务实的”，追求的设计选择是合理的，以最大限度地提高用户便利性，但似乎总是倾向于他们的政治和商业利益。

In this world, social media apps will not use some fancy design involving frequently rotating session keys.

在这个世界上，社交媒体应用程序不会使用一些涉及频繁轮换会话密钥的奇特设计。

Instead, they will just use one app-specific ID for each user - and because the ID system is one-per-person, each user will only be able to have one account (as opposed to "weak ID" like eg.

相反，他们只会为每个用户使用一个特定于应用程序的 ID，而且由于 ID 系统是一人一个，因此每个用户只能拥有一个帐户（与“弱 ID”不同，例如：

Google accounts today, where it's reasonably feasible for an average person to get ~5 accounts).

如今的 Google 帐户，平均每个人获得约 5 个帐户是相当可行的）。

In the real world, pseudonymity generally requires having multiple accounts : one for your "regular identity" and others for any pseudonymous identities (see " finsta and rinsta ").

在现实世界中，假名通常需要拥有多个帐户：一个用于您的“常规身份”，其他帐户用于任何假名身份（请参阅“finsta 和 rinsta”）。

Hence, the practical level of pseudonymity that you get is plausibly lower than today's status quo, and so under one-per-person ID, even if ZK-wrapped, we risk coming closer to a world where all of your activity must de-facto be under a single public identity .

因此，您获得的实际假名水平似乎低于当今的现状，因此，在每个人一个 ID 的情况下，即使采用 ZK 包装，我们也有可能接近这样一个世界：您的所有活动实际上都必须在单一公共身份下进行。

In a world of growing risk (eg.

在风险日益增加的世界中（例如。

drones), taking away the option for people to protect themselves through pseudonymity has significant downsides.

无人机），剥夺人们通过假名保护自己的选择权有很大的缺点。

If you do not publish your secret s , no one can see the public link between your various accounts.

如果您不公开您的秘密，则没有人可以看到您的各个帐户之间的公共链接。

But what if someone does?

但如果有人这么做了怎么办？

A government could force someone to reveal their secret, so that they can see their entire activity.

政府可以强迫某人透露他们的秘密，以便他们可以看到他们的整个活动。

This is not theoretical: the US government is already starting to require visa applicants to make their social media accounts public.

这不是理论上的：美国政府已经开始要求签证申请人公开他们的社交媒体帐户。

Additionally, employers can easily make revealing your full public profile a condition of employment.

此外，雇主可以轻松地将披露您的完整公开资料作为雇用条件。

Even individual applications could technically require revealing your identities on other applications as a condition of joining (in fact, "Sign In With [app]" does this by default).

从技术上讲，即使是单个应用程序也可能需要在其他应用程序上透露您的身份作为加入的条件（事实上，“使用 [app] 登录”默认情况下会执行此操作）。

Again, in these situations, the value of the ZK property falls away, but the downside of the new "one account per person" property remains.

同样，在这些情况下，ZK 财产的价值会下降，但新的“每人一个账户”财产的缺点仍然存在。

It is possible to design these schemes to make coercion more difficult: for example, you could use a multi-party computation to generate each app-specific ID, involving the user and the service.

可以设计这些方案来使强制更加困难：例如，您可以使用多方计算来生成每个应用程序特定的 ID，其中涉及用户和服务。

This would make it impossible for a user to prove their app-specific ID for a particular application without the application operator's participation.

这将使用户无法在没有应用程序运营商参与的情况下证明其特定应用程序的应用程序特定 ID。

This raises the difficulty of demanding that someone reveal their entire identity - but it does not eliminate the possibility, and such schemes have other downsides, eg.

这增加了要求某人透露其全部身份的难度 - 但这并不能消除这种可能性，而且此类计划还有其他缺点，例如。

requiring the application developer to be a live entity instead of something like a passive onchain smart contract.

要求应用程序开发人员是一个实时实体，而不是被动的链上智能合约。

These edge cases are most harmful in the case of systems that try to maintain a one-per-person property, and they have nothing to do with privacy; hence, ZK does not help.

这些边缘情况对于试图维护每人一个财产的系统来说是最有害的，而且它们与隐私无关；因此，ZK 没有帮助。

Among the purist cypherpunks, a common proposed alternative to attempting any kind of identity system is to rely entirely on proof-of-wealth as anti-sybil.

在纯粹的密码朋克中，尝试任何类型的身份系统的一个常见替代方案是完全依赖财富证明作为反西比尔。

You can prevent someone from easily creating a huge number of accounts, by making each account cost some amount of money.

您可以通过让每个帐户花费一定金额来防止某人轻松创建大量帐户。

This has precedent on the internet; for example, the Somethingawful forum required a one-time fee of $10 to create an account, which would be forfeited if you get banned - though this was not truly cryptoeconomic in practice, because the hardest part of creating a new account is not replacing the $10, it's getting a new credit card.

这在互联网上已有先例；例如，Somethingawful 论坛要求一次性支付 10 美元来创建帐户，如果你被禁止，这笔费用将被没收 - 尽管这在实践中并不是真正的加密经济，因为创建新帐户最困难的部分不是取代 10 美元，而是获得一张新的信用卡。

Potentially, you can even make the payments conditional : to get an account, you only put the funds up at stake, and lose the funds in the rare case that you get banned.

您甚至可以设置有条件的付款：要获得一个账户，您只需将资金投入抵押，并在极少数情况下被禁止时损失资金。

This theoretically makes it possible to raise the stakes much higher.

从理论上讲，这使得可以提高赌注。

This can work well in many types of situations.

这在许多类型的情况下都可以很好地发挥作用。

But there are some classes of situations where this kind of approach does not work at all.

但在某些情况下，这种方法根本不起作用。

I will talk about two primary classes, which I will describe as " UBI-like " and " governance-like ".

我将谈论两个主要类别，我将其描述为“类 UBI”和“类治理”。

By a UBI-like situation, I mean a situation where there is value in giving a very wide (ideally universal) set of users some quantity of assets or services, regardless of their ability to pay.

我所说的类似 UBI 的情况是指为非常广泛（理想情况下是通用的）用户提供一定数量的资产或服务是有价值的，无论他们的支付能力如何。

Worldcoin does this systematically: anyone with a World ID gets a small but regular ongoing supply of WLD tokens.

Worldcoin 系统地做到了这一点：任何拥有 World ID 的人都会获得少量但定期持续供应的 WLD 代币。

Plenty of token airdrops have done this in a more informal way, trying to get at least a few of their tokens in the hands of as many of their users as possible.

许多代币空投都以一种更非正式的方式做到了这一点，试图将至少一些代币交到尽可能多的用户手中。

Personally, I do not expect such tokens to be worth anywhere close to enough to pay for a person's subsistence.

就我个人而言，我并不认为此类代币的价值足以支付一个人的生存费用。

In a 1000x richer AI-powered economy, they could be, but in such a world government-run programs backed by natural resource wealth if nothing else would continue to be much more economically meaningful.

在一个富裕了 1000 倍的人工智能驱动的经济中，它们可能会实现，但在这样一个世界中，如果没有其他东西能够继续具有更大的经济意义，那么由自然资源财富支持的政府运行的计划就可以了。

Rather, I think the realistic problem that such mini-UBIs solve is giving people access to a sufficient quantity of cryptocurrency to make a few basic onchain transactions and online purchases .

相反，我认为这种迷你 UBI 解决的现实问题是让人们能够获得足够数量的加密货币来进行一些基本的链上交易和在线购买。

This could include things like:

这可能包括：

If cryptocurrency is very widely adopted worldwide, this stops being a problem.

如果加密货币在全球范围内得到广泛采用，那么这就不再是一个问题。

But while cryptocurrency is not very widely adopted worldwide, this can be a lifeline for people to gain access to onchain non-financial apps and to online goods and services that would otherwise not be accessible at all.

尽管加密货币在全球范围内并未得到广泛采用，但这可能成为人们访问链上非金融应用程序以及根本无法访问的在线商品和服务的生命线。

There is also another way to accomplish a similar thing: "universal basic services".

还有另一种方式可以完成类似的事情：“普遍的基础服务”。

Give each person with an identity the ability to send a limited number of free transactions within a particular application .

让每个拥有身份的人都能够在特定应用程序中发送有限数量的免费交易。

This approach is potentially more incentive-aligned and capital-efficient, because it can be done by each application that benefits from such adoption, without needing to pay for non-users, though this comes with the tradeoff of being less universal (users only get guaranteed access to participating applications).

这种方法可能更具激励性和资本效率，因为它可以由受益于这种采用的每个应用程序来完成，而无需为非用户付费，尽管这会带来不太普遍的权衡（用户只能保证访问参与的应用程序）。

But here too, you need an identity solution to protect the system from spam, without the exclusionary nature of requiring payment via a payment method that perhaps not everyone has access to.

但在这里，您也需要一个身份解决方案来保护系统免受垃圾邮件的侵害，而不需要通过可能并非每个人都可以使用的付款方式进行付款的排他性。

A final important category to highlight is the " universal basic security deposit ".

最后要强调的一个重要类别是“全民基本保证金”。

One of the functions of identity is to have something that can be targeted for punishment, without requiring the user to put up an amount of capital at stake equal to the size of the incentive.

身份的功能之一是拥有可以作为惩罚目标的东西，而不需要用户投入与激励规模相等的资金数额。

This also serves the goal of making participation less contingent on how much capital you have (or the need to have any capital at all).

这也有助于使参与不再取决于您拥有多少资本（或根本不需要拥有任何资本）。

Consider the case of a voting system (eg.

考虑投票系统的情况（例如

likes and retweets on a social media platform).

在社交媒体平台上点赞和转发）。

If user A has 10x the resources of user B, then they have 10x the voting power.

如果用户 A 拥有用户 B 10 倍的资源，那么他们拥有 10 倍的投票权。

But each unit of voting power benefits user A 10x more (in economic terms) than it benefits user B (because A is bigger, and so A gains or loses more in economic terms from everything).

但每单位投票权给用户 A 带来的好处（从经济角度来看）比给用户 B 带来的好处多 10 倍（因为 A 更大，所以从经济角度来看，A 从一切事物中获得或损失更多）。

Hence, in total, A's vote benefits A 100x more than B's vote benefits B.

因此，总的来说，A 的投票给 A 带来的好处比 B 的投票给 B 带来的好处多 100 倍。

For this reason, we would expect A to put far more effort into showing up to vote, determining how to vote to maximize their goals, and perhaps even being strategic in manipulating algorithms.

出于这个原因，我们预计 A 会投入更多的精力去投票，决定如何投票以最大化他们的目标，甚至可能在操纵算法方面采取战略性措施。

This is the basic reason why whales in coin voting schemes have an outsized effect.

这就是为什么鲸鱼在硬币投票计划中产生巨大影响的根本原因。

Here is a more general, deeper reason why a governance system would not want to give equal weight to $100,000 controlled by one person and $100,000 split between 1,000 people: the $100,000 split between 1,000 people represents 1,000 different people, and so it's more likely to incorporate a higher volume of valuable information, as opposed to a smaller volume of information blasted at high volume.

这是一个更普遍、更深层的原因，说明为什么治理系统不希望对一个人控制的 100,000 美元和 1,000 人之间分配的 100,000 美元给予同等的重视：1,000 人之间分配的 100,000 美元代表 1,000 个不同的人，因此它更有可能包含更多有价值的信息，而不是大量传播的较小信息量。

The signal from 1,000 different people is also likely to come more "muted", because its different component signals from the different people will often cancel each other out.

来自 1,000 个不同人的信号也可能变得更加“静音”，因为来自不同人的不同分量信号通常会相互抵消。

This applies both to formal voting systems, and also to "informal voting systems" , such as people's ability to participate in the evolution of the culture by making public statements.

这既适用于正式投票系统，也适用于“非正式投票系统”，例如人们通过发表公开声明参与文化演变的能力。

What this shows is that a governance-like system would not truly be satisfied with treating each equal-sized bundle of dollars the same regardless of provenance.

这表明，类似治理的系统不会真正满足于对每一笔同等规模的美元一视同仁，无论其来源如何。

The system has an interest in knowing the internal coordination level of the bundle of dollars.

系统有兴趣了解美元束的内部协调水平。

Notice that if you accept the frame that I use to describe both cases (UBI-like and governance-like), then technically the explicit need for any kind of one-person-one-vote falls away.

请注意，如果您接受我用来描述这两种情况的框架（类似 UBI 和类似治理），那么从技术上讲，对任何形式的一人一票的明确需求就会消失。

Identity is still very useful in both cases - but the requirement for it to follow any kind of strict one-per-person rule is no longer there.

在这两种情况下，身份仍然非常有用 - 但不再需要它遵循任何严格的一人规则。

From the above arguments, we can see that there are two pressures that bound from opposite ends the desired difficulty of acquiring multiple identities in an identity system:

从上面的论证中，我们可以看到，在身份系统中获取多重身份的难度受到来自两端的两种压力的限制：

Taking these arguments together, we want it to be as easy as possible to get multiple identities, subject to the constraints of (i) limiting the power of large-scale actors in governance-like applications, (ii) limiting the ability to exploit UBI-like applications.

综合这些论点，我们希望尽可能容易地获得多个身份，但受到以下约束：(i) 限制大规模参与者在类似治理的应用程序中的权力，(ii) 限制利用类似 UBI 的应用程序的能力。

If we draw directly from the mathematical models for governance-like applications in the previous section, then we get a very clean answer: if having N identities gives you N² power, then the cost of getting N identities should be N² .

如果我们直接从上一节中类似治理的应用程序的数学模型中得出，那么我们会得到一个非常清晰的答案：如果拥有 N 个身份给你 N² 权力，那么获得 N 个身份的成本应该是 N² 。

And, it just so happens, this is a satisfactory answer for UBI-like applications as well.

而且，碰巧的是，这对于类似 UBI 的应用程序来说也是一个令人满意的答案。

Long-time readers of this blog may notice that this looks exactly like the chart from an earlier post on quadratic funding .

该博客的长期读者可能会注意到，这看起来与之前有关二次融资的文章中的图表完全相同。

This is not a coincidence.

这并非巧合。

By "pluralistic identity", I mean an identity regime where there is no single dominant issuing authority, whether that's a person, or an institution, or a platform.

我所说的“多元身份”是指一种身份制度，其中没有单一的主导发行机构，无论是个人、机构还是平台。

This can be accomplished in two ways:

这可以通过两种方式完成：

A recent snapshot of the Circles identity graph.

Circles 身份图的最新快照。

Circles is one of the largest live running social-graph-based identity projects.

Circles 是最大的实时运行的基于社交图谱的身份项目之一。

Explicit pluralistic identity naturally bakes in the capacity for pseudonymity : you can have a pseudonymous identity (or even multiple), and each of those identities can build up reputation in their communities through their actions.

明确的多元化身份自然会带来假名的能力：您可以拥有一个假名身份（甚至多个），并且每个身份都可以通过他们的行为在其社区中建立声誉。

An ideal explicit pluralistic identity system may not even need to have the concept of discrete identities; rather, you might have an amorphous cloud of your provable past actions, and prove different parts of it in a fine-grained way as needed for each action.

理想的显式多元身份系统甚至可能不需要离散身份的概念；相反，您可能拥有可证明的过去行为的无定形云，并根据每个操作的需要以细粒度的方式证明它的不同部分。

Zero-knowledge proofs will make pseudonymity easier, because you can use your primary identity to bootstrap a pseudonym, by privately providing the first signal that the new pseudonym should be taken seriously (eg.

零知识证明将使假名变得更容易，因为您可以使用您的主要身份来引导假名，通过私下提供应认真对待新假名的第一个信号（例如

ZK-proving ownership of some quantity of coins to post from anon.world , or perhaps one can ZK-prove some claim about what kind of Twitter followers one has).

ZK-证明对从 anon.world 发布的一定数量的硬币的所有权，或者也许人们可以 ZK-证明一些关于一个人拥有什么样的 Twitter 粉丝的声明）。

There may well be even more effective ways of using zero-knowledge proofs.

很可能有更有效的方法来使用零知识证明。

Implicit pluralistic identity has a "cost curve" which is steeper than quadratic, but still has most of the right properties .

隐式多元身份有一条比二次方更陡的“成本曲线”，但仍然具有大多数正确的属性。

Most people have some of the forms of ID that I've listed in this post, but not all.

大多数人都有我在这篇文章中列出的一些身份证明形式，但不是全部。

You can get one more form of ID with some effort, and the more forms of ID you get, the less favorable the benefit/cost ratio of getting the next one.

您可以通过一些努力获得更多形式的身份证明，并且您获得的身份证明形式越多，获得下一种身份证明的收益/成本比就越不利。

Hence, it provides the needed brake on governance attacks and other abuse, while still ensuring that there is no fixed set of IDs that a coercer can demand, and reasonably expect, you to reveal.

因此，它为治理攻击和其他滥用提供了必要的制动，同时仍然确保强制者不会要求并合理地期望您透露一组固定的 ID。

Any form of pluralistic identity (implicit or explicit) is naturally more error-tolerant : someone with disfigured hands or eyes would still likely have a passport, and a stateless person would still likely have access to some non-state way of proving that they are a person.

任何形式的多元身份（隐性或显性）自然都更容错：手或眼睛被毁容的人仍然可能拥有护照，无国籍人仍然可能有机会使用某种非国家方式来证明他们是一个人。

Note that these properties break if any one form of ID gets close to 100% market share, and it becomes realistic to demand it as a sole login option .

请注意，如果任何一种形式的 ID 占据接近 100% 的市场份额，这些属性就会失效，并且要求将其作为唯一的登录选项变得现实。

This to me is the biggest risk that could come from identity systems that try too hard to be "universal": if their market share gets too close to 100%, they shift the world from the pluralistic identity to a one-per-person model, which has worse properties for the reasons I described in this post.

对我来说，这可能来自那些过于努力“通用”的身份系统：如果它们的市场份额太接近 100%，它们就会将世界从多元化身份转变为一人一模式，由于我在这篇文章中描述的原因，这种模式具有更糟糕的特性。

In my view, the ideal outcome of "one-per-person" identity projects that exist today is if they were to merge with social-graph-based identity.

在我看来，当今存在的“一人一个”身份项目的理想结果是它们与基于社交图谱的身份融合。

The largest problem that social-graph-based identity projects have is scaling to a very large number of users.

基于社交图谱的身份项目面临的最大问题是扩展到大量用户。

One-per-person identity systems could be used to bootstrap social graphs, creating millions of "seeds", at which point there would be enough adoption to safely grow a globally distributed social graph from that point forward.

一人一身份系统可用于引导社交图谱，创建数百万个“种子”，届时将有足够的采用来安全地从那时起发展全球分布的社交图谱。