AES CCM 8 byte MIC?

[Fredrik]

Basically I want to get a 8 byte long MIC when using the AES CCM encryption. From the product specification it does seem like I can only get a 4 byte MIC, is that correct? Or is there some workaround available?

[ovrebekk]

Hi Fredrik

Any particular reason you need such a large MIC?
It seems a bit overkill.

The AES CCM module in the chip is designed for BLE primarily, and follows the BLE specification. In other words there is no 8 byte MIC available.

If you skip the CCM entirely and only use the AES module then you could handle the MIC generation in software, allowing you to use any size MIC, but then you will obviously take a hit to performance and code size.

Best regards
Torbjørn