Photography Security

I am looking for some solutions to keeping photographs secure with WordPress. I am currently using Zen Photo to organize pictures for a client and it keeps being hacked.

He is a local sports photographer and sells his pictures to family members and newspapers. He wants to show off his photography but he is worried about people being able to download them. Zen Photo had a watermark and made the images difficult to download using the save as command.

Any answers, plugins, or hacks that could work for me?

Thanks

Coach Kip