Research On VoIP Speech Information Hiding And Extracting Algorithm Based On ILBC Encoding

With the development of VoIP(Voice over Internet Protocol),privacy leaks and data security problems occur frequently,and the traditional ways of secure communications can not satisfy the needs of users.Information hiding is a new way of achieving secure communications by concealing the secret information,thus protecting users from privacy leaks efficiently.A new algorithm for speech information hiding is proposed based on complete binary tree dividing dynamic codebook obtained from iLBC.The algorithm realizes dynamic codebook partition by combining the dynamic codebook and QIM(Quantization Index Modulation)principle with the complete binary tree.To embed the secret information,the sender selects the corresponding codebook according to the secret information bits and then the receiver extracts the secret information according to the features of the codeword vectors.In addition,to deal with the defect of bit position reversal in the least significant bits replacement algorithm,a speech information hiding algorithm based on parameter modification is proposed.The algorithm detects and modifies the least significant parameters(LSP)of iLBC encoding parameters,which realizes the embedding of secret information.The receiver extracts the secret information according to the features of parameters to achieve covert communications.In order to verify the security of the algorithms,experimental platform in LAN(Local Area Network)is built,and the software with the function of speech information hiding is deployed.The imperceptibility of the algorithm is evaluated by waveform,PESQ(Perceptual Evaluation of Speech Quality),ABX,and MCD(Mean Cepstrum Distortion),and the robustness is evaluated by adding noise attacks.The results show that these two algorithms could embed 450 b and 33 b per second respectively,and also have good imperceptibility and robustness,which meets the requirements of VoIP for real-time covert communications.