A secured chaos encrypted mode-S aircraft identification friend or foe (IFF) system

This paper introduces a new technique for aircraft identification friend or foe (IFF). The technique is based on using a proposed Chaos Advanced Encryption Standard (AES) with mode-S IFF. AES has a key size of 128 bits and a substitution-linear transformation network with 10 rounds. The sensitivity of the chaos initial condition gives the algorithm the ability to use as a second key. The first key was assigned using a soft look-up table used periodically. The second key was assigned using the date of the current day by both interrogator and the transponder. This technique gives the system more security and confidentiality which is compatible with mode-S IFF interrogation and reply messages format. It requests a new data on the reply signal. This data increase the radar performance for detection and tracking the friend targets in active and passive jamming environments. The results obtained from this technique on the simulated interrogator and transponder signals shows that this scheme can be easily implemented and provide the air defence system a secured aircraft authentication.