The keys allotted in pairs by PKI decided the embedding and extracting processes of the watermarking and seal.The electronic seal includes two layers of fragile watermark and robust digital watermark.

• 方案中使用PKI分配成对的密钥完成水印和印章的嵌入及检测提取，电子印章里分别包含有具有脆弱和鲁棒特性的两层水印。