Hi there, Probably a very basic question, I’ve successfully created an Arduino Pro Mini + RFM95 node that sends data. I used the sample here: things4u/LoRa-Thing/blob/master/LoRaWAN_V31-htu-lowpower/LoRaWAN_V31-htu-lowpower.ino /************************************************************…

Unless you’re not giving us all details, you’re wrong when thinking the data is still encrypted when using TTN Console. See Decrypting messages for dummies .

Thank you for the reply. I’m sending a simple string “TTT” to the gateway, and what I receive in the payload is: 8E EF 60 It’s sent here: things4u/LoRa-Thing/blob/master/LoRaWAN_V31-htu-lowpower/LoRaWAN_V31-htu-lowpower.ino#L175 //Initialize RFM module RFM_Init(); //Construct data mem…

The answer is in the topic I linked too, so you’ll need to read that first before asking for more help. [image] chbla: The sample uses AES encryption. If you still think so after reading the other topic: where’s the code for that?

I read the topic, what exactly are you referring to? If it would be HEX only when arriving on TTN it would be 3 times the same if I send TTT, or not? The encryption is done here: things4u/LoRa-Thing/blob/master/libraries/LoRaWAN_V30/LoRaMAC_V10.cpp#L109 unsigned char MIC[4]; //Unc…

[image] chbla: what I receive in the payload is: 8E EF 60 That’s in the gateway. When looking at your device’s data in TTN Console, TTN will have decrypted for you, like explained in the other topic. And true, the LoRaWAN libraries will encrypt (but your own sketch won’t), but TTN will decry…

I’m not sure if I follow. 8E EF 60 is in the TTN console, under the data tab. The sketch I use uses LORA_Send_Data() as shown above, and LORA_Send_Data() as in my last message contains Encrypt_Payload(). So I assume it is encrypted (hence I do get 3 distinct values in TTN if I send “TTT”) I guess? …

[image] chbla: 8E EF 60 is in the TTN console, under the data tab. That’s weird. Unless the specific sketch is doing additional encryption, that should not happen when using TTN Console to administer applications and devices. I think sprintf(msg,"TTT"); should not cause that either. Sorry, I…

When using ABP, then I guess TTN Console cannot know if the correct Application Session Key (AppSKey) was used. For uplinks, the Message Integrity Code (MIC) is calculated using the secret Network Session Key (NwkSKey), not the AppSKey. But even when TTN determines the packet’s MIC is valid, decryp…

Thanks for the pointers. I forgot to mention that I use msb - the reason being that with lsb I did not see any data at all . With msb I actually received. However, I now saw in your link that lmic requires lsb, which is confusing as I don’t receive anything then. Do all of the values need to be in…

I think: If you see packets in a gateway’s Traffic page then you only know it’s connected; you don’t know if the keys are okay. (Though maybe peeking into the “trace” part might give you some hints about TTN knowing the recipient.) If you see data in a device’s Data page, then the DevAddr and …

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Decrypt AES encoded payload?

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arjanvanb (Arjan) January 8, 2018, 1:42pm 13

See:

What is the difference between OTAA and ABP Devices
How often should a node do an OTAA Join, and is OTAA better than ABP?