Encrypted speech authentication and recovery scheme based on fragile watermarking

In order to solve the problems that most of the existing speech authentication algorithms can only realize tamper localization of frames, and need to the additional recovery information during tamper recovery, an encrypted speech authentication and recovery scheme based on fragile watermarking was proposed by using least significant bit method (LSB) and linear interpolation method. Firstly, a scrambling encryption algorithm based on Henon mapping is designed to encrypt and decrypt speech. Secondly, the frame number of ciphertext speech is used to construct fragile watermarking information. Finally, the LSB method is used to embed the watermarking into the fourth place after the decimal point of encrypted speech for authentication, and residial-based linear interpolation method is used to tamper recover the unauthenticated speech. The experimental results show that the proposed scheme can realize the tamper detection and location of sampling points, and the restored tampered content has good auditory quality.