Confused about which VPN is right, US senator asks the NSA for guidance

对该选哪款 VPN 感到困惑？美国参议员要求美国国家安全局（NSA）提供指导

A prominent US senator is asking the National Security Agency to provide guidance to the general public on best practices for using virtual private networks to secure their communications from spying by foreign adversaries. 一位著名的美国参议员正要求美国国家安全局（NSA）向公众提供关于使用虚拟专用网络（VPN）的最佳实践指南，以保护其通信免受外国对手的窥探。

VPNs funnel all of a user’s Internet traffic through an encrypted connection to a remote server. The design provides strong assurances that no one between the user and the server can read the encrypted contents. VPNs also allow users to hide their IP addresses from the destination servers they communicate with. While US agencies have previously recommended use of VPNs, none have given recommendations on which ones provide adequate protection. VPN 将用户的所有互联网流量通过加密连接传输到远程服务器。这种设计提供了强有力的保证，即用户和服务器之间的任何人都无法读取加密内容。VPN 还允许用户向其通信的目标服务器隐藏自己的 IP 地址。虽然美国政府机构此前曾建议使用 VPN，但从未就哪些 VPN 能提供足够的保护给出过建议。

It’s all in the nuances

细节决定成败

There are a host of limitations that can undo many of the protections users may think their VPN provides them. For instance, the encrypted tunnel often terminates once a single server decrypts the traffic and sends it on to its final destination. That means the decrypted traffic or the sending and destination IP addresses may be available for snooping by rogue employees or attackers who hack the server. VPNs also don’t encrypt certain types of metadata, such as time stamps, allowing nation-states to build profiles that can be useful in intelligence gathering. 有许多局限性可能会抵消用户认为 VPN 所提供的保护。例如，一旦单个服务器解密流量并将其发送到最终目的地，加密隧道通常就会终止。这意味着解密后的流量或发送方和接收方的 IP 地址可能会被流氓员工或黑客攻击服务器的攻击者窥探。VPN 也不会加密某些类型的元数据（如时间戳），这使得民族国家能够建立可用于情报收集的个人资料。

With so many nuances, the existing recommendations to use a VPN don’t provide enough information for people to make informed decisions. Sen. Ron Wyden (D-Ore.) is asking the NSA to provide specific recommendations. 由于存在如此多的细微差别，现有的使用 VPN 的建议并没有提供足够的信息供人们做出明智的决定。参议员罗恩·怀登（Ron Wyden，俄勒冈州民主党人）正要求 NSA 提供具体的建议。

“Americans facing advanced foreign threats—including government personnel, defense contractors, journalists, and human rights defenders—deserve clear, honest advice about how best to protect their communications from surveillance by foreign adversaries,” Wyden wrote in a letter sent Wednesday to Gen. Joshua Rudd, the director of the NSA. “To that end, I request that you update NSA’s existing public guidance on VPN configurations to address this issue.” “面临先进外国威胁的美国人——包括政府人员、国防承包商、记者和人权捍卫者——理应获得关于如何最好地保护其通信免受外国对手监视的清晰、诚实的建议，”怀登在周三致 NSA 局长约书亚·拉德（Joshua Rudd）将军的信中写道。“为此，我请求你们更新 NSA 现有的关于 VPN 配置的公共指南，以解决这一问题。”

Specific questions touch on some fairly technical details, including the general architecture of a VPN service. They include the adequacy of single-hop VPNs, which, as noted earlier, use a single server to decrypt traffic sent by the user and send it to its destination. It also asks about multi-hop architectures, in which the traffic is funneled through two or more servers, allowing the first to see only the IP address of the sender and the terminating server to see only the destination address. The letter also inquires about the use of random delays and cryptographic padding to thwart attacks that detect timing patterns or the size of messages. 具体问题涉及一些相当技术性的细节，包括 VPN 服务的一般架构。其中包括单跳 VPN 的充分性，如前所述，它使用单个服务器来解密用户发送的流量并将其发送到目的地。信中还询问了多跳架构，在这种架构中，流量通过两个或多个服务器传输，允许第一个服务器仅看到发送者的 IP 地址，而终止服务器仅看到目标地址。信中还询问了使用随机延迟和加密填充来挫败检测时间模式或消息大小的攻击。

Wyden further asks about the adequacy of specific services such as Apple Private Relay, Nym, and Tor. The questions are: 怀登进一步询问了 Apple Private Relay、Nym 和 Tor 等特定服务的充分性。问题如下：

1. Are standard, single-hop commercial VPNs sufficient to protect Americans’ sensitive digital footprints from foreign adversaries monitoring internet backbones?

2. 标准的单跳商业 VPN 是否足以保护美国人的敏感数字足迹免受监控互联网骨干网的外国对手的侵害？

3. Does the NSA recommend multi-hop tools such as Apple Private Relay, Tor, or Nym over standard VPNs for Americans facing heightened surveillance threats?

4. 对于面临更高监视威胁的美国人，NSA 是否建议使用 Apple Private Relay、Tor 或 Nym 等多跳工具，而不是标准 VPN？

5. What technical features, such as random delays, padding, and cover traffic, are needed to defend against sophisticated surveillance, and how does the NSA assess multi-hop systems like Apple Private Relay compared with Tor and Nym?

6. 防御复杂的监视需要哪些技术特性（如随机延迟、填充和掩护流量），以及 NSA 如何评估 Apple Private Relay 与 Tor 和 Nym 相比的多跳系统？

Nym is an open source VPN client written in Rust, a memory-safe programming language that’s resistant to attacks exploiting buffer overflows or other types of memory-corruption bugs. Nym can route traffic through a decentralized “mixnet,” which provides random time delays and the reordering of messages. The VPN can also provide a multi-hop architecture. Apple Private Relay provides multi-hop browsing using two servers, one operated by Apple and the other by a third-party content provider. Tor is a privacy service that encrypts traffic and sends it through three servers before decrypting it and sending it to its final destination. Nym 是一个用 Rust 编写的开源 VPN 客户端，Rust 是一种内存安全的编程语言，能够抵御利用缓冲区溢出或其他类型内存损坏漏洞的攻击。Nym 可以通过去中心化的“混合网络”（mixnet）路由流量，该网络提供随机的时间延迟和消息重排序。该 VPN 还可以提供多跳架构。Apple Private Relay 使用两台服务器提供多跳浏览，一台由苹果运营，另一台由第三方内容提供商运营。Tor 是一种隐私服务，它对流量进行加密，并通过三台服务器传输，然后再解密并发送到最终目的地。

Each of the services comes with pros and cons. The hops provided by Nym and Tor, for example, are operated by volunteers, some of whom may be nation-state spies trying to use their vantage point to gather intelligence. Apple Private Relay relies on content delivery networks like Cloudflare and Akamai that not everyone trusts. Its protection is also limited to the Safari browser running on Apple devices. 每种服务都有其优缺点。例如，Nym 和 Tor 提供的跳点由志愿者运营，其中一些人可能是试图利用其有利位置收集情报的民族国家间谍。Apple Private Relay 依赖于 Cloudflare 和 Akamai 等并非所有人都信任的内容分发网络。其保护范围也仅限于在苹果设备上运行的 Safari 浏览器。

A memo issued by the Congressional Research Service provides an overview of the options but provides no criteria for determining which ones are best. That leaves many people unable to make informed choices about what’s best for their threat model. 国会研究服务处发布的一份备忘录概述了这些选项，但没有提供确定哪些选项最好的标准。这使得许多人无法就最适合其威胁模型的方案做出明智的选择。

“There’s no trustworthy standardization” for assessing various VPN services, Micah Sherr, a Georgetown University professor specializing in network security, said in an interview. “The VPN ads you get in YouTube commercials can be incredibly misleading. It’s extremely difficult for ordinary users to determine whether they need a VPN, what a VPN actually buys them, and which one to use.” 乔治城大学专门研究网络安全的教授 Micah Sherr 在接受采访时表示：“目前还没有评估各种 VPN 服务的可信标准化体系。你在 YouTube 广告中看到的 VPN 广告可能会极具误导性。普通用户很难确定他们是否需要 VPN，VPN 实际上能为他们带来什么，以及该使用哪一个。”

Wyden requested that the NSA provide answers no later than October 14. 怀登要求 NSA 在 10 月 14 日之前提供答复。