I am building app that will serve some content to the users via my private server. At the server-side I would like to identify user, so that I don’t serve same content twice to the same user. How can I identify user(s)?
One way is DeviceID, but user can have multiple devices…?
Is the only way to have my own user IDs for my application (registration). I don’t like this as it adds extra complexity to the app.
I know it’s a hard task, but maybe facial recognition (from the webcam) could help in logging in users, since it doesn’t imply any relation between user and device.
For example, face.com offers a free web-based API for facial recognition.
Although, Ishu‘s answer (username/password) is the easiest and most standard way to do identify users.