Encrypted packet decrypted incorrectly (bad CRC)

[andreribeiro423]

Hi! I'm using the nRF52-DK development kit to implement secure communications via Bluetooth Low Energy (BLE) on Zephyr. I'm pairing an nRF52-DK with my smartphone via LE Secure Connections with Just Works (BLE Security Mode 1 Level 2). To verify the exchanged BLE packets I'm using an nRF Dongle with Wireshark as a BLE Sniffer. However I am having problems decrypting some ATT packets as I have seen the error "Encrypted packet decrypted incorrectly (bad CRC)" on Wireshark. I turned on the notifications for a characteristic and got this error a few times. I leave below images of what happened on Wireshark.

I look forward to any help, thank you!

[Hung Bui]

Hi Andre,

It's showed in the error "(Bad CRC)". This indicate that the sniffer captured a corrupted message. The CRC of the packet doesn't match with the CRC calculated from the package. 
Because of the the sniffer couldn't decrypt the package. 
It is pretty normal for a radio communication that from time to time the package is corrupted, maybe due to interference.

If it doesn't happen so often you can safely ignore them.