Hi Paul, > Has anyone found a way to integrate some kind of protection against > unauthorized distribution of ecw images? If we are to send a > client an ecw > on a CD, there really isn't anything except honesty to stop them from > passing the CD out to everyone and their brother.
While this is true, it isn't really specific to ECW, it has been a "problem" since satellite data was first put on mag tape many decades ago. it is a lot easier and cheaper to copy stuff nowdays though, but data is generally also a lot cheaper. > I have contacted > Globetrotter software; they said that they really have no solution but it > could be done with an executable that manages the ecw (the ecw would be > inside the executable) or by on the fly encryption/decryption. Basically yes, and this can be done by a 3rd party using the ECW SDK now. > The on the > fly encryption/decryption seems as if it would decrease performance > substantially. This would depend a lot on the algorithm used, and the level of encryption required. Really though it's going to be a lot faster to decrypt the data than read if from CD/DVDROM. > Does anyone have any experience in ecw protection > that they > might share? Thank you. Some thing to consider is that if you want to put encrypted ECW's on the CD, someone can usually still copy the CD, and just give the decryption key (eg, a password or certificate) to someone else. Unless you are going to tie the encryption to some unique aspect of the clients system (network card MAC address etc) it will be fairly easily crackable by someone determined enough to do it. Also, a sophisticated encryption scheme may cost more than the data - eg, a VeriSign certificate can be relatively expensive. Basically what I'm coming back to is that IMO if the data is cheap enough, and updated often enough, people will buy it, and annoying 95% of the legitimate honest users with a sophisticated encryption system that stops them backing up their data CD's and jacks up the purchase price to prevent the 5% who might pirate it (but probably won't buy it either way) probably isn't the way to go. regards -- Simon ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^ Simon Cope, : e-mail: [EMAIL PROTECTED] Chief Software Architect : WWW: http://www.ermapper.com : Int'l Phone: +61 8 9388 2900 Earth Resource Mapping Pty Ltd, : Int'l Fax: +61 8 9388 2901 Level 2, 87 Colin St, West Perth. : Australia Phone: (08) 9388 2900 Western Australia 6005 : Australia Fax: (08) 9388 2901 Q: 1.2TB (1,200GB) Image over the Internet? A: Image Web Server! http://www.earthetc.com > > > Paul Lohr > > > ----------------------------------------------------------- > > To make changes to your subscription, please visit our website, > http://www.ermapper.com/technicl/ermapperl/index.htm > > ----------------------------------------------------------- To make changes to your subscription, please visit our website, http://www.ermapper.com/technicl/ermapperl/index.htm
