--- title: Spy Tech: The GPS Numbers Station | daily.dev description: Researcher Steven Murdoch from University College London analyzed over 12 million GPS packets spanning 2007 to 2026, investigating a mysterious 176-bit field... canonical: https://daily.dev/posts/spy-tech-the-gps-numbers-station-gudc6dsze twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Spy Tech: The GPS Numbers Station | daily.dev og:description: Researcher Steven Murdoch from University College London analyzed over 12 million GPS packets spanning 2007 to 2026, investigating a mysterious 176-bit field... og:url: https://daily.dev/posts/spy-tech-the-gps-numbers-station-gudc6dsze og:image: https://api.daily.dev/og/posts/gUDc6dsZe.png og:image:alt: Spy Tech: The GPS Numbers Station og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Spy Tech: The GPS Numbers Station **[Hackaday](https://daily.dev/sources/hackaday)** · 2 min read · 1 upvotes · 0 comments ## Summary Researcher Steven Murdoch from University College London analyzed over 12 million GPS packets spanning 2007 to 2026, investigating a mysterious 176-bit field called Subframe 4, Page 17 in the L1 C/A GPS navigation message. The GPS specification labels it for 'special messages' but provides no further detail. Murdoch's best hypothesis is that the field is used for cryptographic rekeying to other systems, effectively functioning as a hidden numbers station embedded in the ubiquitous GPS signal. The research also demonstrates interesting data analysis techniques using Python, Julia, and other tools, with source code publicly available. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Schneier on Security](https://daily.dev/posts/schneier-on-security-a0hqg0sfd) · Schneier on Security · 0 upvotes · 0 comments - [The GPS III Rollout Is Almost Complete, But What Is It?](https://daily.dev/posts/the-gps-iii-rollout-is-almost-complete-but-what-is-it--hwmjyhqir) · Hackaday · 0 upvotes · 0 comments - [Bad Connection: Uncovering Global Telecom Exploitation by Covert Surveillance Actors](https://daily.dev/posts/bad-connection-uncovering-global-telecom-exploitation-by-covert-surveillance-actors-0xrralmoy) · Hacker News · 0 upvotes · 0 comments --- Tags: [#python](https://daily.dev/tags/python), [#cryptography](https://daily.dev/tags/cryptography) [View this post on daily.dev](https://daily.dev/posts/spy-tech-the-gps-numbers-station-gudc6dsze) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Spy Tech: The GPS Numbers Station","url":"https://daily.dev/posts/spy-tech-the-gps-numbers-station-gudc6dsze","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/spy-tech-the-gps-numbers-station-gudc6dsze"},"datePublished":"2026-06-08T15:58:03.829Z","dateModified":"2026-06-08T15:58:22.594Z","description":"Researcher Steven Murdoch from University College London analyzed over 12 million GPS packets spanning 2007 to 2026, investigating a mysterious 176-bit field...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/cb0e6cf8160b6c6609649a3a7dfe3144?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/cb0e6cf8160b6c6609649a3a7dfe3144?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hackaday","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hackaday","logo":"https://media.daily.dev/image/upload/s--JhDfhy70--/f_auto,q_auto/v1767541814/logos/hackaday","url":"https://daily.dev/sources/hackaday"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/spy-tech-the-gps-numbers-station-gudc6dsze","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"python,cryptography","timeRequired":"PT2M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hackaday","item":"https://daily.dev/sources/hackaday"},{"@type":"ListItem","position":3,"name":"Spy Tech: The GPS Numbers Station"}]} ```