11 Replies Latest reply on Nov 17, 2009 7:13 AM by kglad

    How to prevent swf files being downloaded

    alysonrainer Level 1

      People,

       

      I'm a teacher and I have some animations made in flash language (swf). I would like to publish these animations on my web site so my students could see, but I wonder if there is any way to prevent these animations being downloaded.

       

      Example: when I see an animation published on my web site, this animation is stored in Internet Temporary Files and I can save this animation anywhere. How can I prevent an animation is stored in the temporary folder? In other words, this animation can only be seen if the user is logged on the site.

       

      Urgent!!!

       

      Thanks.

      Alyson

        • 1. Re: How to prevent swf files being downloaded
          kglad Adobe Community Professional & MVP

          you can't.  if a swf is viewed in a web browser, it's in the viewer's cache.

          • 2. Re: How to prevent swf files being downloaded
            alysonrainer Level 1

            Thanks a lot for the answer, but there is any way that I can erase de cache so that the user can't get it?

            • 3. Re: How to prevent swf files being downloaded
              kglad Adobe Community Professional & MVP

              no.  it would be a substantial security risk if you were able.

              • 4. Re: How to prevent swf files being downloaded
                moccamaximum Level 5

                You could implement a kind of time-barrier, like in the trial versions you download from softwarecompanys.

                For the most users, that are not understanding actionscript and know how to read the code, even if they decompile it, that would prevent the swf being played after a certain date that you would have to implement in your code.

                In AS2 the code would be like this:

                 

                var now:Date = new Date(); //reads the user system date
                var release:Date = new Date(2009, 11, 16); //here goes the date, when you want to have the program deactivated

                 

                if(now <= release){

                   playSwf(); // here goes your normal code

                }

                 

                else{

                   doNothing();

                }

                 

                Like the most TimeBarriers this could be easily circumvented if the user sets back his system date, so do not give a message like "You trial period has expired"

                • 5. Re: How to prevent swf files being downloaded
                  alysonrainer Level 1

                  I think that's what I want. I found a site that has exactly what I need. It

                  is done this way too?

                   

                  Plese take a look at http://www.edumedia-sciences.com/en/a559-scintigraphy

                  <http://www.edumedia-sciences.com/>

                   

                  Thanks

                   

                   

                   

                  2009/11/16 moccamaximum <forums@adobe.com>

                   

                  You could implement a kind of time-barrier, like in the trial versions you

                  download from softwarecompanys.

                  For the most users, that are not understanding actionscript and know how to

                  read the code, even if they decompile it, that would prevent the swf being

                  played after a certain date that you would have to implement in your code.

                  In AS2 the code would be like this:

                  >

                  var now:Date = new Date(); //reads the user system date

                  var release:Date = new Date(2009, 11, 16); //here goes the date, when you

                  want to have the program deactivated

                  >

                  if(now <= release){

                     playSwf(); // here goes your normal code

                  }

                  >

                  else{

                     doNothing();

                  }

                  >

                  Like the most TimeBarriers this could be easily circumvented if the user

                  sets back his system date, so do not give a message like "You trial period

                  has expired"

                  >

                  • 6. Re: How to prevent swf files being downloaded
                    moccamaximum Level 5

                    Hard to tell what is behind this. My guess is, they use a mediaplayer that can play swf and a xml to point the player to the right swf. The moment the actual simulation is running in a browser you could save it (No demo available so I can`t tell for sure). If you really look for a way to encrypt your swf and say make it dependent on a user`s authentification you have to really go the hard way, and that means: AIR, to save a kind of authentification file on the users computer, to tie it to the hardware or a encrypted password, also you will possibly have to use Flash Media Server, but that would mean 4000$ +.

                    But I`m not sure if thats not cracked already. I`m currently trying to develop an application where I try to tie PDF-Manuals, that run inside an AIR-Environment to an accounts`details and have done an extensive search around security in the Flash-Field, and must say that I have my doubts that anyone other than Adobe can produce secure Flash files.

                    • 7. Re: How to prevent swf files being downloaded
                      R7AF Level 1

                      How about creating a screen-movie, possibly with interaction (mouse visible) and voice over, and publishing that? If a flash movie can be played in a browser, it has to be decrypted in the browser, and that means it could be cracked.

                      • 8. Re: How to prevent swf files being downloaded
                        moccamaximum Level 5

                        These guys claim to have the perfect solution : http://nitrolm.com/

                        There is a free version one year up to a 100 customers.

                        Should be sufficient for 3-4 classes of yours

                        • 9. Re: How to prevent swf files being downloaded
                          alysonrainer Level 1

                          Moccamaximum,

                           

                          I really think these guys have the perfect solution.

                           

                          I'll try to use the free version and, if it works, I'll buy the commercial

                          one.

                           

                          I would like to thank you for taking the time to try to solve the problem

                          and for the great answers provided. I wrote this same question in more than

                          8 specialized forums and almost all the answers were that was not possible

                          to protect swf files.

                           

                          Thus, it may take some time for me to learn how to do this, but as soon as I

                          learn I will notice if it really worked.

                           

                          Thanks a lot for all the help and please let me know if you find other new

                          way to do this.

                          My best regards,

                           

                          Teacher Alyson Rainer

                          2009/11/17 moccamaximum <forums@adobe.com>

                           

                          These guys claim to have the perfect solution : http://nitrolm.com/

                          There is a free version one year up to a 100 customers.

                          Should be sufficient for 3-4 classes of yours

                          >

                          • 10. Re: How to prevent swf files being downloaded
                            moccamaximum Level 5

                            You`re welcome. Actually it surprised me, that this could be done. So I learned a lot myself.

                            • 11. Re: How to prevent swf files being downloaded
                              kglad Adobe Community Professional & MVP

                              the answers you received on those 8 forums were correct:  it's not possible to prevent your swf's download.  you can make it more difficult but, you can't prevent it.