found: Work cat.: 2001099790: Disappearing cryptography, c2002:t.p. (Watermarking)
found: ASTI on FirstSearch, May 15, 2002(descriptor: Digital watermarks)
found: EI, May 15, 2002(descriptor: Digital watermarking)
found: LC database, May 15, 2002(in title: digital watermarking)
found: Wikipedia, viewed June 19, 2018(under Steganography tools: allows a user to embed hidden data inside a carrier file, such as an image or video and later extract that data; further related articles give examples: stegomalware, digital watermarking)