I looked it up a couple of years ago (I think at nikonusa.com or nikonpro.com) and remember that it was several hundred dollars. See note at http://www.nikonusa.com/Service-And-Support/Service-Advisories/gpailmpu/Image-Authentication-Software.html It is now an archived Product Product Number: 25738. This may in part to a vulnerability found that allowed false authentication to occur. You may still be able to get the product, though. I recall that the authentication attached only to the raw, or .nef file. Any jpgs did not carry the authentication itself. I shoot everything with authentication turned ON in the camera and thus I could always authenticate later if anything is ever challenged. If you're working on the prosecution or plaintiff side, I think noting that you shot authenticated images should be enough notice to the folks on the other side of the case. The authentication seems to take very little space in terms of file size, so shooting authenticated is easy. If you go through the process of getting and installing the reader, I'd be interested in hearing about your experience.