摘要： This article presents an advanced dual chaotic watermarking scheme to improve information security. To ensure confidentiality in digital image transmission, a secure dual watermarking scheme is proposed by applying the chaotic logistic system and hyper-chaotic dynamical system. Chaotic watermarking was conducted in the spatial domain, where suboptimal secure hashing with a variable length was selected in preprocessing stages. The secret key was generated by the chaotic sequence for pixel shuffling using a chaotic logistic map, so that a controlled amount of distortion was inserted into the host digital image. Watermarking was proceeded after the chaotic watermark had been embedded into the shuffled image. To strengthen the security, the hyper-chaotic system was used to generate chaotic blocks for block scrambling in order to achieve dual chaotic watermarking. Characteristics analysis was conducted for multiple examples in both spatial and frequency domains. Potential effects induced by the chaotic driving parameter on processing time and integrity authentication of chaotic dual watermarking were also analyzed in detail.