Fetal electrocardiogram changes in relation to fetal heart rate patterns during labor.
Studies on body area sensor networks are drawing increasing attention for the medical treatment and personal healthcare. Due to stringent constraints of power, memory and computation capability, security mechanism in wireless body area sensor networks should be quite different from generic sensor networks. This paper proposes a specific symmetric cryptosystem for those networks wherein physiological signals derived from the human body are utilized to generate key and also assure the safety of key transmission. The results of experimental data analysis show that the binary sequences extracted from photoplethysmographic signal have acceptable randomness and thus can be used to generate key in the proposed cryptosystem.