Well time-travel is indeed at this moment very unlikely if you're referring to time travel as taking a trip to the Middle Ages. It would be possible of the existence of a time hard disk drive, like a computer that saves everything you did on it, like the history of your browser. Then in theory it would be possible to time travel. That of course opens the debate as how time then is sorted. Is it linear, meaning from point A to B to C etc. and when go back, we actually influence the future and create a new linear history. Is it not linear, but in fact goes into multiple directions, making it so that going back doesn't change the future or going back is in fact part of the flow of time or that alternate timelines are created. Regarding that last one there is a theory that every second millions of new timelines are created based on the things you do. For instance that you decide to take a turn to the left and on that moment other timelines are created one where you go to the right, another you go straight forward, another back.
Teleportation has a bigger chance of being possible. I don't know whether this has been proven or not, but in the least it was a theory, namely that 'space' can be molded. That it for instance can pressed downwards and maybe it could even be folded like a paper. There is a theory that worm holes are in fact that, folded space and that through the worm hole you end up somewhere else in the Universe. So in theory it then could be possible for instance to say building a machine where you give in the coordinates of a certain place on Earth and that machine then compresses that space with where you are currently and linking them with each other.
Another topic that hasn't been mentioned yet I think is mind reading. I can understand that it can be found out which part of the brain is responsible for which action, but if I think words in my head or even just imagine a picture, is it even possible to read or view that? I mean is there somewhere in my brain a place that actually shows that picture or words on the moment I'm thinking of them, encrypted or not?