The attached ZIP file contains a collection of GFSK-modulated downlink recordings for the device with device ID
004d33db and NAK (key)
479e4480fd7596d45b0122fd282db3cf. Use the downlink demodulation script to demodulate these recordings. The audio files were produced using GQRX's I/Q recording functionality and were captured in close proximity to the base stations in Grafenberg (48°33’59” N 9°18’43” E) or Dettingen unter Teck (48°36’49” N 9°26’43” E).
meta.csv file contains relevant metadata such as the downlinks' corresponding uplink SNs. It also contains both the scrambled and descrambled downlink frame (in HEX).
The scrambled downlink frame can be decoded using
renard (if your renard version comes with downlink scrambling support - the scrambling algorithm was not published at 35C3):
$ renard dldecode -f 975c7d44939d63b7acccfcefb51dc0 -i 004d33db -k 479e4480fd7596d45b0122fd282db3cf -s 16c deadbeefdeadbeef