A digital watermarking apparatus inputs video or audio information and embeds digital watermark in the information, which is capable of preventing digital watermark or set values necessary for digital watermarking operation from being altered. The apparatus includes a verifying section, a decrypting section and a watermarking section. The verifying section verifies encrypted set values using verification data in set values which is added with verification data and encrypted together with verification data, and transmits the verification result to the watermarking section. The verifying section also transmits the encrypted set values which are verified to the decrypting section. The decrypting section decrypts the encrypted set values. The watermarking section embeds digital watermark in the information using the decrypted and verified set values to output it, when a verification result from the verifying section is normal. When the verification result is not normal, the watermarking section does not output the input information to the outside of the apparatus.