Abstract: A novel secret communication model using watermarking technology is presented．In this scheme，the plaintext of secret information is first encrypted with the private key，then the encrypted code is embedded into a database，and the watermarked database is transferred to the receiver via open media．The receiver first retrieves the encrypted massage，then decrypts it with the sender’s public key to get the plaintext.The secret communication model is proposed，with the corresponding embedding and extracting algorithms devised.Experimental results show that the scheme is hard to detect，more secure，practical and expandable.

Key words: secret communication, information hiding, digital watermark, relational database

摘要： 针对开放环境中秘密通信的安全性问题，提出一种基于信息隐藏技术的秘密通信方案。首先，将信息明文用私钥加密，然后将密文以数字水印的形式嵌入到载体数据库中，通过开放网络传送。接收者需要从载体数据库中提取信息密文，再用发送方的公钥解密。给出了秘密通信的系统模型以及相应的信息嵌入、提取算法。实验和分析表明该模型隐蔽性强、安全性好，有一定的实用性和可扩展性。

关键词: 秘密通信, 信息隐藏, 数字水印, 关系数据库