[RESOLVED] Simple way to disable right-click image save as OR mask/replace image name?

Joseph_Sliker

Hi; I'm creating a simple facial recognition script. It will show the pictures of other users and the person taking the test will have to pick each person's name from a drop-down next to each picture.

It's just for fun and I don't have to be utterly obsessive about security (ie. I won't try to disable view source code) BUT a very simple cheat would be to right-click the image: most users will figure out from the picture name who the picture is.

Is there a simple way to simply not allow a person to right click on ANY image shown on a page? If there is not, is there a way to put some bogus name in the "save image as" name box?

Thanks in advance.

bradgrafelman

Moved to ClientSide Technologies forum.

There are some simple Javascript solutions out there to disable right-click menus, but note that all it would take to circumvent them is to disable Javascript (or view the source code of the page).

Joseph Sliker wrote:
If there is not, is there a way to put some bogus name in the "save image as" name box?

Sure... use "some bogus name" for the actual name of the file.

Weedpacket

Like bradgrafelman suggests; it would be app-wide (rename all user images to something unreadable - a cryptographic hash of their name, perhaps - and the picture's filename would have to be stored in the table as well (unless you do base it on a hash of their username, I guess...).

But there are even simpler cheats than right-clicking: Firefox at least lets you click-and-drag an image to the desktop.

bradgrafelman wrote:
but note that all it would take to circumvent them is to disable Javascript

In fact Firefox has a setting specifically for disallowing scripts from overriding the context menu.

Joseph_Sliker

I don't think I explained myself very well. On a single page visitor will see a series of pictures of fellow users: one after another. Next to each one will be a drop-down selector with the list of user names. The visitor selects a name for each picture, and upon submitting, sees who he has correctly identified (or not) and/or a percent correct score.

The series of pictures are named whatever the username is, plus .jpg. Obviously the correct username.jpg will have to be used if the correct picture is to be fetched and displayed for each item. If the user right-clicks the picture to "save as", can the save as text box be somehow instructed to show something else (or nothing at all) rather than the username?

bradgrafelman

Joseph Sliker wrote:
can the save as text box be somehow instructed to show something else (or nothing at all) rather than the username?

No - that's browser-side functionality that you can't change. You could try to do some clever tricks like overlaying a transparent gif on top of the image (e.g. using a CSS z-index value), but they could still simply view the source of the page (assuming you aren't using something nifty like AJAX, which it sounds like you could).

Joseph Sliker wrote:
Obviously the correct username.jpg will have to be used if the correct picture is to be fetched and displayed for each item.

Why does the image have to be named the same as the username? Why can't you use a salted hash of the username (or something similar) instead?

Weedpacket

Joseph Silker wrote:
The series of pictures are named whatever the username is, plus .jpg. Obviously the correct username.jpg will have to be used if the correct picture is to be fetched and displayed for each item.

Yeah, I got that; I was kind of implying that this is your main problem: you're telling them the answer at the same time you're asking the question: For which instrument was Mendelssohn's Violin Concerto composed?

Joseph_Sliker

Okay. I guess I can't do this without some significant redesign work (that would involve several sections which also depend on the pictures). At the moment this is just a trivial little app..no performance records are saved, and there are no cash prizes involved: it's just a bit of fun to help people learn the names of infrequently-encountered colleagues. If they use the right-click to cheat, it's a victimless crime.

Thanks for educating me on the issues involved!