Separate Enciphering of Correlated Messages for Confidentiality in Distributed Networks

This paper studies distributed joint secrecy and compression suitable for sensor networks. A capacity region that characterizes the tradeoff between compression and secrecy is derived. We demonstrate for the two-node case that under the restriction of separate enciphering (i.e., no inter-node collaboration) unconditional secrecy by both parties cannot be achieved simultaneously. A fundamental design rule for lightweight encoder implementation critical for secrecy based on distributed source coding using syndromes and Reed-Solomon codes is presented highlighting practical feasibility.