NSA最新幻灯片曝光：详解棱镜项目工作流程

北京时间6月30日上午消息，《华盛顿邮报》昨天独家披露了美国国家安全局(NSA)“棱镜”(PRISM)项目的四张幻灯片。这些文件详细揭示了 整个项目的工作流程，包括NSA和美国联邦调查局(FBI)的审查和监管权限。另外，它们还显示了该项目与所涉九家互联网公司的互动方式。
　　1. 获取新目标的数据

　　这张幻灯片描述了NSA分析员在PRISM系统中建立新监控目标的流程。建立新目标的请求会自动发送到审查搜索关键词的主管。主管必须批准分析员的“合理意见”，即收集数据时指定目标为海外的外籍人士。
外国情报监视法庭不审批任何个人数据收集请求外国情报监视法庭不审批任何个人数据收集请求
　　左：FBI使用装在私人公司(例如微软、雅虎)的政府设备检索匹配的信息，不经进一步审查便交给NSA。
　　中：外国情报监视法庭不审批任何个人数据收集请求
　　右1：对于存储的通信记录(非实时监控)，FBI会查询其数据库，确保筛选器不会匹配任何知名美国人。
　　右2：数据从此处进入NSA系统。
　　2. 分析从私人公司收集到的信息

　　获取通信信息后，由专门的系统处理语音、文字、视频以及地理位置、监控目标的设备特征等“数字网络信息”。
　　左：FBI装在私人公司的截获设备将信息传递给NSA、CIA或FBI。
　　3. 每个目标分配一个案例代号

　　PRISM案例代号格式反映了实时监控和存储内容的可用情况。
　　每当监控目标登录或发送电子邮件时，NSA可收到实时通知，另外还可实时监控语音通话和文字消息，具体情况视PRISM数据提供方而定。
　　4. 搜索PRISM数据库

　　这张幻灯片显示，4月5日PRISM的反恐数据库中由11.7675万活跃的监控目标。它未显示监控这些目标的过程中“无意”收集了多少其他互联网用户以及多少美国人的通信信息。

文章来源： http://goo.gl/03kw2
附原文：

NSA slides explain the PRISM data-collection program

The top-secret PRISM program allows the U.S. intelligence community to gain access from nine Internet companies to a wide range of digital information, including e-mails and stored data, on foreign targets operating outside the United States. The program is court-approved but does not require individual warrants. Instead, it operates under a broader authorization from federal judges who oversee the use of the Foreign Intelligence Surveillance Act (FISA). Some documents describing the program were first released by The Washington Post on June 6. The newly released documents below give additional details about how the program operates, including the levels of review and supervisory control at the NSA and FBI. The documents also show how the program interacts with the Internet companies. These slides, annotated by The Post, represent a selection from the overall document, and certain portions are redacted. Read related article.

New slides published June 29

Acquiring data from a new target

This slide describes what happens when an NSA analyst "tasks" the PRISM system for information about a new surveillance target. The request to add a new target is passed automatically to a supervisor who reviews the "selectors," or search terms. The supervisor must endorse the analyst's "reasonable belief," defined as 51 percent confidence, that the specified target is a foreign national who is overseas at the time of collection.

The FBI uses government equipment on private company property to retrieve matching information from a participating company, such as Microsoft or Yahoo and pass it without further review to the NSA.

For stored communications, but not for live surveillance, the FBI consults its own databases to make sure the selectors do not match known Americans.

This is where data enters NSA systems, described more fully on the next slide.

The Foreign Intelligence Surveillance Court does not review any individual collection request.

See the inner workings of the NSA's top secret spy program »

Analyzing information collected from private companies

After communications information is acquired, the data are processed and analyzed by specialized systems that handle voice, text, video and "digital network information" that includes the locations and unique device signatures of targets.

From the FBI's interception unit on the premises of private companies, the information is passed to one or more "customers" at the NSA, CIA or FBI.

PRINTAURA automates the traffic flow. SCISSORS and Protocol Exploitation sort data types for analysis in NUCLEON (voice), PINWALE (video), MAINWAY (call records) and MARINA (Internet records).

The systems identified as FALLOUT and CONVEYANCE appear to be a final layer of filtering to reduce the intake of information about Americans.

Each target is assigned a case notation

The PRISM case notation format reflects the availability, confirmed by The Post's reporting, of real-time surveillance as well as stored content.

Depending on the provider, the NSA may receive live notifications when a target logs on or sends an e-mail, or may monitor a voice, text or voice chat as it happens (noted on the first slide as "Surveillance").

Searching the PRISM database

On April 5, according to this slide, there were 117,675 active surveillance targets in PRISM's counterterrorism database. The slide does not show how many other Internet users, and among them how many Americans, have their communications collected "incidentally" during surveillance of those targets.

Original slides published June 6

Introducing the program

A slide briefing analysts at the National Security Agency about the program touts its effectiveness and features the logos of the companies involved.

The program is called PRISM, after the prisms used to split light, which is used to carry information on fiber-optic cables.

This note indicates that the program is the number one source of raw intelligence used for NSA analytic reports.

The seal of
Special Source Operations, the NSA term for alliances with trusted U.S. companies.

Monitoring a target's communication

This diagram shows how the bulk of the world’s electronic communications move through companies based in the United States.

Providers and data

The PRISM program collects a wide range of data from the nine companies, although the details vary by provider.

Participating providers

This slide shows when each company joined the program, with Microsoft being the first, on Sept. 11, 2007, and Apple the most recent, in October 2012.