Electromagnetic Compatibility of the Military Handset with Hidden Authorization Function Based on MIL-STD-461D Results

Abstract

In this paper we present algorithm and hardware architecture of the new military communication device dedicated for VHF battlefleld radio stations. The results of the compati- bility tests carried out for this device according to the norm MIL-STD-461D are also presented together with the flgures and comments. Measurements were carried out at the Electromagnetic Compatibility Laboratory, Faculty of Electronics, Military University of Technology. The Lab- oratory have accreditation given by the Polish Centre for Accreditation for carrying out those military devices measurements. Described results of measurements will be a base for introduction this developed device into the Polish Armed Forces equipment. One of the most important security problems unsolved till this time in the communications links is voice authorization of the telephone or radio subscriber. Problem is more obvious when it is considered both current voice communications over digital and analog channels: VoIP, PSTN, GSM and state-of-the-art real-time, artiflcial, speech synthesis in the context of potential risk of impersonating, known in information technology as a Presented algorithm and hardware architecture are the proposals for increasing security level in unprotected voice calls, as a response to a new telephone attacks named \voice spooflng. At present, subscriber's authorization in telephone calls is performed in the most cases in sub- jective way using our Human Auditory System. Well known scheme of subjective authorization is based on knowledge of dedicated speciflc person's voice. New scheme of the authorization is based on objective way using watermarking (data hiding) technology. Additional binary signature as a inaudible watermark is embedded in the host's signal voice in the radio or telephone handset and then transmitted over communications links. At the receiving side, using dedicated hardware based on real-time processing algorithm, watermark is extracted and binary signature is compared with the set of binary signatures storage in the handset's memory. Results of the authorization process is displayed on handset's LCD. Hardware architecture of the handset is based on the fast, ∞oating- point Digital Signal Processor TMS320C6713 and microcontroller ARM7TDMI family. Handset transmits, watermarked, analog voice, using standard voice interface in the TRC9200 battlefleld VHF PR4G radio station family.