chart image of a session can be accessed in another session using url of the chart image, how to prevent this?

for e.g, one user generated pie/bar chart and chart image shows url when you right click:

https://asdfasdfadsfadfadfadf.com/ChartImages/Chart_27.png?KxRx=0x07870

another user can user this url to see the chart eventhough he doesnt have access to generate this report.

i saw a method "deployment scenario", can i use this method to say seq num is 0, so that it wont store the image in the filesysem but nt sure whether it will generate error.

my question is i want to generate chart but doesnt want to store it.

Thank you