Photector is a Cydia tweak that allows you to protect your photos from being deleted. You can download the tweak for free in Cydia, and it comes with two built-in modes. The first mode allows you to password protect your photos by requiring a password every time someone clicks on the delete button on a photo. The second mode allows you to make the delete button on photos useless, which is a mode if you want superb protection. The only way to delete photos with this option on is to disable the tweak momentarily (which is an option in the settings for the tweak). You can get photector from Cydia for free and its available under the BigBoss repo.