A digital watermarking apparatus that embeds two watermarks in host data is provided. The first watermarking block generates a plurality of watermarking location candidates of the first watermark, and embeds the first watermark into the respective location candidates of the host data, and then selects one candidate with a high level of robustness as the first watermarked host data. The second watermarking block scrambles the watermarking location information on the first watermark and thereby generates a plurality of the second watermark candidates. Then the second watermarking block embeds the respective second watermark candidates in the first watermarked host data and selects one candidate with a high level of robustness as the second watermarked host data.