HarperCollins has started using Digimarc Corp.’s watermarking system for e-books to provide an extra layer of security to the sale of HC’s digital content.

According to Chantal Restivo-Alessi, chief digital officer for HC, the addition of Digimarc’s Guardian Watermarking for Publishing product is another step to prevent leaks in the digital supply chain as the company adds more e-tailers throughout the world.

Although the system is capable of identifying consumers who download e-books illegally, HC is using it to make sure that its e-tailers “are using the highest degree of security possible,”Restivo-Alessi said. If the Guardian Watermarking finds e-books that are being downloaded illegally, they will ask that e-tailer to either upgrade their security efforts or risk being dropped as an account, Restivo-Alessi added.

The addition of the watermarking initiative to regular DRM efforts “is another control we have in the digital supply chain to assure authors we are doing all we can to protect their content,”Restivo-Alessi said. HC has been aggressively growing its sales of e-books overseas and just last week signed an agreement with JD.com to sell e-books in China.

In addition to HC, LibreDigital has adopted the use of Digimarc watermarking technology. Watermarking, which embeds digital watermarks in an e-book, is beginning to gain traction in the book industry, a Digimarc spokespersons said, emphasizing that their Guardian Watermarks do not contain any personal or user information but only “anonymous digital IDs.”