[Tinyos Core WG] CC2420 Security Discussion

[JeongGil Ko (John Ko)]

Hi.

I just wanted to clarify the status of cc2420 security on our side.

- Interface generalization
The interfaces CC2420Key and CC2420SecurityMode can both be generalized 
for supporting multiple platforms (we looked at RF231 and CC2520).

- 802.15.4 compatibility
The current implementation is not 802.15.4 compatible. We do not follow 
the 802.15.4 security header format and we also do not provide a way for 
the upper layer to  implement all the 15.4 related security features. To 
make the implementation 802.15.4 compatible, the first step we can take 
is to change the security header to comply with the standards. By doing 
this we will be able to keep the complexity of the code low and support 
most of the 15.4 security options (but not the full set).

Another approach that we can can take is to build primitives that allow 
support for all the 802.15.4 security features. This would require a 
more sophisticated API and a more complicated code than we have right 
now. For CC2420 (which needs to do decide how to decrypt without taking 
the packet out from the RX FIFO) this solution can also incur 
significant overhead and cause more packets to be missed.

I can fix the header format to match the 15.4 standards but for the 
second approach I will need more help from the group.

Thanks.

-John

-- 
JeongGil (John) Ko
Ph.D. Student
Department of Computer Science
Johns Hopkins University
http://cs.jhu.edu/~jgko