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View Full Version : Problem with different file extensions using PTCrypt from Pr


TomKa
15th of July 2003 (Tue), 16:28
Testing to display encrypted pictures with PTCrypt in the EE-Gallery I end up with a different file extension for the encrypted full resolution panorama picture :

thumb: pano1.jpg
microthumb: pano1.jpg
full image - encrypted: pano1.jpa (or pano1.jpb or pano1.jpc)

Is there some workaround in photo.php line 1435 for the value:
"">"
to set a extension for the filename that is different from the thumb image (pano1.jpg) so the result is:
""

example:
thumb image: pano1.jpg
full image to display: pano1.jpc


From the PTCrypt documentation:
PTCrypt is a utility to encrypt images for web use. Encrypted images can be used in PTViewer version 1.8 and above or in the decrypt applet included with this utility. They offer some protection against theft which otherwise is easy from WWW-sites or CD-Roms.

PTCrypt offers three levels of Protection:
Encoding using a fixed, built-in digital key (Extension ".jpa"). Images encrypted using this method can not be read and opened by any standard Graphics-program, eg Photoshop, Paintshop or GraphicConverter. Images can still be used as source for the PTViewer applet. Therefor, although not able to open the image, a thief might still use it in connection with PTViewer.
Encoding using a variable key containing the path to the HTML-page (Extension ".jpb"). As before, images can not be opened by ordinary Graphics-programs. Additionally, PTViewer can only open the image, if it is located at the correct position in the filesystem of the computer. Copying the file from the WWW or a CD to the local drive effectively disables PTViewer, which no longer can read the image. The image can still be loaded if the whole filesystem with corresponding pathnames is duplicated on the thief's computer.
Encoding using a variable key containing the URL to the HTML-page (Extension ".jpc"). This is very similar to point 2 above, except that the top domainname is also part of the key. This makes duplicating the filesystem ineffective and provides even more protection. However, it may cause problems, if the server has multiple domain-names, because only one will work. There are also problems using this method with CDs, since the CD-drive's name is part of the URL and may change among systems.

Pekka
17th of July 2003 (Thu), 12:36
In EE 1.5 I have a way to deal with all possible image output choices needed - I'll just add a switch to photo: "encrypted: yes/no" and it loads different "viewerstyle" for main photo output. This viewerstyle (e.g. "pt_crypted.php") then handles file suffix conversion on the fly and displays the image using PTview applet, so photos are stored on server as jpg - you will have to upload the images manually though, as Imagemagick or GD does not support PTCrypt encoding AFAIK.

It should be noted though that using PTview forces you to keep images on same server as EE.

TomKa
17th of July 2003 (Thu), 13:12
That's great, I'm very curious about version 1.5 (and to start with a bit of translation work).