5 ms·

OTOH if the OEM can't code the CRC right, one might be better off packing their own parachute...

• Odenwaelder 8y ago
  No, you're not better off. If you want to get a medical product like this licensed, you have to prove that you performed rigorous, multi-staged testing and document all your development including all emerging risks. I have participated in such licensing efforts and I doubt that an open source project has the means of providing such rigorous testing.
  • stefan_ 8y ago
    The result of this diligent process, of course, is how a broken CRC16 routine got shipped in this medical product. It's the most trivial thing. Copy a public domain CRC16 routine, add a unit test with a test vector.
    • joezydeco 8y ago
      Can you be sure it wasn’t a badly implemented form of obsfucatiom? It certainly slowed down the reverse engineers. If they didn’t get to the object code what would the next step have been? Cryptographic analysis?
      • stefan_ 8y ago
        5 of the bits were never set in their "obfuscated" variant? If you want to obfuscate CRC16 you would just choose a randomized starting value.
        • joezydeco 8y ago
          I didn't say it was implemented well. Perhaps they should changing shift operators would quietly change the values without any disturbance to checksum integrity.
  • mikelward 8y ago
    Tidepool is indeed working on FDA approval for Loop. https://www.tidepool.org/blog/tidepool-delivering-loop https://www.tidepool.org/blog/tidepool-delivering-loop