Provably Secure Public-Key Steganography Based on Elliptic Curve Cryptography

Steganography is the technique of hiding secret messages within seemingly harmless covers to elude examination by censors. Despite having been proposed several decades ago, provably secure steganography has not gained popularity among researchers due to its rigorous data requirements. Recent advancements in generative models have enabled these researchers to provide explicit data distributions, which has contributed to the development of provably secure steganography methods. However, these methods depend on the assumption of a preshared key. In practical settings, these methods face various challenges, including key agreement, key updating, and user expansion. Although public-key steganography provides a viable solution, existing public-key steganography approaches are burdened with inefficiency and complex implementation in practical scenarios. In this paper, we proposes a practical public-key steganography method based on elliptic curve cryptography and a generative model. This method is the first comprehensive and practical approach to public-key steganography and steganographic key exchange. Additionally, we provide a specific instance to illustrate the proposed method. The security of the proposed construction is also proven based on computational complexity theory. Further experiments have demonstrated the security and efficiency of the proposed method.