In 2013, the world learned the name XKeyscore. Edward Snowden leaked slides detailing the National Security Agency’s (NSA) most expansive internet surveillance system. The intelligence community scrambled, and the public was outraged. But for years, the actual mechanics of the software remained a black box.
The leaked configuration files show that XKEYSCORE can target users based on behavior rather than identity. Examples of coded rules include flag parameters for:
Once metadata fields are extracted, they are run against a local dictionary of targeted selectors. These include: Email addresses and usernames IP addresses and subnets Unique tracking cookies or session tokens Hardware identifiers like MAC addresses or IMEI numbers The Query Language: Rules and Triggers
The exclusive breakdown of its architecture reveals three primary layers: 1. The Collection Forwarder (The Sniffer)
The source code for XKeyscore is highly exclusive, and access is strictly limited to authorized NSA personnel and trusted partners. The code is not shared with other government agencies or private companies, and it is not publicly available. xkeyscore source code exclusive
: According to the report, users of the privacy-focused OS Tails were categorized in the code as "extremists." Even visiting a Linux forum to discuss Tails could trigger a flag for deeper surveillance.
Perhaps the most telling aspect of the leaked source code is the library of "App IDs." These are modules designed to parse and interpret specific internet protocols.
Nearly a decade after the first documents were revealed, the story of the NSA’s XKEYSCORE remains one of the most chilling chapters in the history of mass surveillance. While Edward Snowden’s original 2013 disclosures shocked the world, it was the subsequent leak of the program’s actual source code that provided an unprecedented, granular look into the machinery of the surveillance state. This article is an exploration of that exclusive leak—its origins, its technical reality, and the ongoing controversy surrounding its authenticity.
The development and maintenance of XKeyscore involve international collaboration between the NSA and its partners, including the Five Eyes intelligence alliance (USA, UK, Canada, Australia, and New Zealand). In 2013, the world learned the name XKeyscore
Beyond tracking specific people, the logic allows for behavioral fingerprinting. For example, a rule can be deployed to flag anyone downloading specific encryption software, visiting specific forums, or using anonymization networks like Tor, simply by analyzing the signature elements of their network requests. Data Fusion and Session Reconstruction
Any connection originating from a specific geographic region that utilizes encryption protocols. Technical Vulnerabilities within the Surveillance State
One line in analyst_api.c is particularly chilling:
The release of these specific source code excerpts led to speculation by researchers at Techdirt and other outlets that there may have been a within the NSA, as some of the data appeared to be from a later date than the original Edward Snowden document cache. Phishing With A Darknet: Imitation of Onion Services - APWG But for years, the actual mechanics of the
Technical blueprints and configuration files reveal that XKEYSCORE relies on a proprietary scripting language and specialized extraction plugins. These components allow analysts to write targeted rules for filtering traffic. Genesis Framework and Plugins
// Conceptual logical flow found within XKeyscore extraction rules if (app_protocol == "http" or app_protocol == "https") if (http_host matches "bridges.torproject.org" or http_request_url contains "tor/status-vote") tag_traffic("ANONYMITY_USER_TOR"); extract_identity_metadata();
Analysts do not query a central database. Instead, they use a web interface to send a query out to all 150+ global sites simultaneously. The local servers search their individual rolling buffers and return the matches. Code Analysis: Deep Dive into the Selectors