| Two thoughts: - I think I would sell this as a private camera app ("protect you and your partner from prying eyes"), rather than by emphasizing the two-party crypto angle ("protect you from your partner"). Like, make the front-line features be: "it's a camera where each photo album is protected by a secret PIN, and if someone takes your phone but doesn't know the PIN, they can't tell the album exists! Oh, and if you want to you can share the album with someone else who has the app, but you can always delete something from the album and it'll be deleted from the shared version as well." This way you're selling it as something that's better than the built in camera app, with some bonus safer-sharing features that will just happen to reduce privacy violations in practice, instead of emphasizing the distrust-of-your-partner-solved-by-easily-hacked-crypto thing. When someone asks their partner to install, it's not "because I don't trust you" but "because it's more private for us." - As a lawyer, I think the legal-prenup-built-into-app approach would be pretty interesting. For example, right now the way US law works, it's much, much easier to get revenge porn taken down if you happen to have been the one holding the camera, than if it was your partner holding the camera. If you were holding the camera you own the copyright, and we have robust legal-technical tools for copyright takedowns, whereas we only have patchy state-based laws around invasion of privacy. So could we have camera apps that actually reallocate the rights between the photographer and subject? Like imagine a shutter button with a bunch of fine print like, "by pressing this button I express an intent to share authorship of the resulting work with all human subjects portrayed, and agree that consent of all authors must be obtained to authorize any copy." I'm not an expert and not sure what would be possible, but it would be interesting to talk to legal advocates in the revenge porn area and ask what legal agreements people could have entered beforehand that would have best protected them, and see if any of them could cleanly be engineered into the UX of a private camera app -- or even into Snapchat et al. |