A new Fresnel holographic watermark hiding method was proposed based on the double-random phase encoding method,the holography and the digital printing technology.The Fresnel transform of the hidden watermark multiplied by a random phase mask is modulated by another random phase mask and superposed by a reference wave,which gives us an encrypted Fresnel hologram.The encrypted Fresnel hologram can be embedded with proper strength into a host image.The hidden information can be recovered from the watermarked ...