--- title: Flume Water Monitor 915 MHz Signal Security – It’s Not Bad description: A security researcher reverse-engineered the 915 MHz RF signal used by the Flume Water Monitor, a consumer IoT device. Using a LimeSDR Mini SDR, they... canonical: https://daily.dev/posts/flume-water-monitor-915-mhz-signal-security-it-s-not-bad-mzmrdjvwo twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Flume Water Monitor 915 MHz Signal Security – It’s Not Bad | daily.dev og:description: A security researcher reverse-engineered the 915 MHz RF signal used by the Flume Water Monitor, a consumer IoT device. Using a LimeSDR Mini SDR, they... og:url: https://daily.dev/posts/flume-water-monitor-915-mhz-signal-security-it-s-not-bad-mzmrdjvwo og:image: https://api.daily.dev/og/posts/mzMRDJVWO.png og:image:alt: Flume Water Monitor 915 MHz Signal Security – It’s Not Bad 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. # Flume Water Monitor 915 MHz Signal Security – It’s Not Bad **[Hacker News](https://daily.dev/sources/hn)** · 3 min read · 0 upvotes · 0 comments ## Summary A security researcher reverse-engineered the 915 MHz RF signal used by the Flume Water Monitor, a consumer IoT device. Using a LimeSDR Mini SDR, they identified 2-FSK modulation at 200 kbps with frequency hopping across 50 channels. The 16-byte payload is encrypted with AES-128 ECB mode, but the effective key strength was reduced from 64 bits to 44 bits by exploiting unencrypted header bytes and a known constant in the key derivation. A GPU-based brute-force attack in Python cracked the key in roughly one day for under $10. The researcher notes that spoofed messages could potentially enable malicious OTA firmware updates, and has responsibly disclosed the findings to Flume, who confirmed plans to improve security. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Snooping Flume Water Monitor Data On The Wire](https://daily.dev/posts/snooping-flume-water-monitor-data-on-the-wire-c5ym7kgqo) · Hackaday · 0 upvotes · 0 comments - [QuadRF can spot drones and see WiFi through my wall](https://daily.dev/posts/quadrf-can-spot-drones-and-see-wifi-through-my-wall-mndsr4njk) · Jeff Geerling · 0 upvotes · 0 comments - [\[PDF\] Is Your Bluetooth Chip Leaking Secrets via RF Signals?](https://daily.dev/posts/pdf-is-your-bluetooth-chip-leaking-secrets-via-rf-signals--oseygahry) · Hacker News · 1 upvotes · 0 comments - [marble 弹珠: "IPv6 over drainage pipe A 40m…"](https://daily.dev/posts/marble-ipv6-over-drainage-pipe-a-40m--jfyjl73rq) · Lobsters · 1 upvotes · 0 comments - [LakeShark firmware turns LilyGO T-Display P4 into a handheld ESP32-P4 SDR scanner](https://daily.dev/posts/lakeshark-firmware-turns-lilygo-t-display-p4-into-a-handheld-esp32-p4-sdr-scanner-pccz99b7f) · CNX Software · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#iot](https://daily.dev/tags/iot), [#reverse-engineering](https://daily.dev/tags/reverse-engineering) [View this post on daily.dev](https://daily.dev/posts/flume-water-monitor-915-mhz-signal-security-it-s-not-bad-mzmrdjvwo) ```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":"Flume Water Monitor 915 MHz Signal Security – It’s Not Bad","url":"https://daily.dev/posts/flume-water-monitor-915-mhz-signal-security-it-s-not-bad-mzmrdjvwo","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/flume-water-monitor-915-mhz-signal-security-it-s-not-bad-mzmrdjvwo"},"datePublished":"2026-07-30T03:21:24.494Z","dateModified":"2026-07-30T03:32:24.287Z","description":"A security researcher reverse-engineered the 915 MHz RF signal used by the Flume Water Monitor, a consumer IoT device. 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