Difference between revisions of "PTCrypt"

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Revision as of 20:30, 13 July 2006

PTCrypt is a Java application created by Helmut Dersch as part of Panorama Tools. It is a tool for encrypting JPEG images to make them viewable by PTViewer only in their original web-page context.

(Note that in the future this page is likely to include tricks for circumventing this particular "Copy Protection" scheme. Please feel free to add any such instructions)

Install

  • make sure Java is installed on your computer
  • download PTcrypt
  • unpack the zip file and put the PTCrypt.jar where convenient to you

Encrypt

  • Double-Click on PTCrypt.jar
  • Enter the path to the image. Example:
http://www.photopla.net/pano.php?id=78&gui=modern
  • Browse to the file you want to encrypt and click "Open"
  • Enter the new file name. Choose the extension based on the kind of encryption you want (see encryption option below).
  • Important: keep a backup copy of the unencrypted JPG.

Encryption Options

Disclaimer: PTCrypt will make stealing panoramas more difficult but not impossible. All encryption scheme supported by PTCrypt have been broken.

JPC: full path

  • Purpose: prevent stealing. The pano will display only when the applet is displayed in an HTML page at the exact URL entered as path.
  • Advantage: strongest PTCrypt protection.
  • Disadvantage: Can't be used with variables URL (such as those that have GET parameters after the question mark). Can't be used within a Windows file system.
  • Examples when it will not display:
http://www.thieves.com/pano.php?id=78&gui=modern
http://www.photopla.net/pano.php?id=78&gui=antique
C:\downloaded\panorama.jpc

JPB: partial path

  • Purpose: more flexibility than JPC
  • Advantage: will run also from a local file system
  • Disadvantage: easy to steal
  • Example when it will display and should not:
http://www.thieves.com/www.photopla.net/pano.php?id=78&gui=modern

JPA: fixed key

  • Purpose: prevent editing.
  • Advantage: most flexible - can be displayed everywhere
  • Disadvantage: no theft protection