Speech authentication and content recovery scheme for security communication and storage

With the rapid development of Internet, it brings a lot of conveniences. However, the data transmission and storage are faced with some security issues that seem to be obstacles to overcome, such as privacy protection and integrity authentication. In this paper, an efficient speech watermarking algorithm is proposed for content authentication and recovery in encrypted domain. The proposed system consists of speech encryption, watermark generation and embedding, content authentication and recovery. In the encryption process, chaotic and block cipher are combined to eliminate the positional correlation and conceal the statistical feature. In the watermark embedding process, approximation coefficients of integer wavelet transform are used to generate watermark and the detail coefficients are reserved to carry watermark. Theoretical analysis and simulation results show that the proposed scheme has high security and excellent inaudibility. Compared with previous works, the proposed scheme has strong ability to detect de-synchronization attacks and locate the corresponding tampered area without using synchronization codes. Meanwhile, the selective encryption will not influence the selective watermarking operation. Similarly, the operation of watermarking will not affect the decryption of the encrypted speech. Additionally, the tampered samples can be recovered without any auxiliary watermark information.