Research On Several Key Multimedia Security Problems Of Command Automation System

Command Automation System(CAS) is the complex electronic-information systemintegrated by some kinds of information. With the wide application of multimediatechnology in CAS, the demand of security assurance of multimedia information becomesmore and more impending. It is the key technique means to realize multimedia informationsecure transmission by encryption and watermarking, which is the hot topic in the filed ofmultimedia security。The dissertation studies the secure transmission problem of multimedia in CAS, suchas military document, speech information and video information. The main contributionscan be enumerated as follows:(1) The multi-level military documents distribution scheme and the correspondingalgorithms are proposed to fulfill content protection and integrality authentication.For realizing authority control and multi-level security, the keys distribution anddeduction algorithm based on Key Managetment Center(KMC) is proposed; For realizingintegrality authentication, the digital signature algorithm is proposed based on onchaotic-neural-network-based one-way Hash function(2) The novel speech secure transmission scheme is proposed to fulfill encryption andcontent authentication.In the part of speech encryption, the block cipher based on chaotic Cat map isproposed; in the part of speech authentication, the audio watermarking algorithm based onexponent proportion quantization in wavelet domain; and the hardware system realizationof the scheme based on DSP is introducted.(3) The video secure transmission scheme and corresponding algorithms facing H.263are proposed to fulfill encryption and content authentication.In this scheme, the improved DEW video authentication algorithm is proposed, thevideo encryption based chaotic key controlling is proposed, and the channel encryptionalgorithm combined with error correction coding.(4) The encryption-watermarking-parallel multimedia secure transmission scheme andthe corresponding scheme are proposed。The parameters choosing strategy is studied; based on stream cipher and QuantizationIndex Modulation (QIM) watermarking algorithm, the encryption-watermarking-parallel multimedia secure transmission schem applied to MPEG2 is proposed.At last, the deficiencies in the dissertation are summarized, and some open issues inthe field as well as the future work are presented.