Technology can usually make you money if you invest in it. It you treat it like a commodity that you should hunt for bargains on, you're shooting your own business in the foot.
There's an algorithm (or two) that leverages multi-step encryption to facilitate two (seemingly exclusive) properties.
The algorithm, developed by Dr. Andrew Neff, was first implemented by a company called VoteHere.
Now it is available for testing and vetting via an implementation at https://vote.heliosvoting.org....
FWIW I've posted about this system almost a dozen times over the past decade.
Both are incredibly well-designed languages with some tricky parts but a lot of smooth sailing.
Swift seems to be solid enough that it's ready for most use cases - or perhaps closer to a quarter or a third of what you need to do every world-class app out there.
If you focus your next few months on Swift you'll be fine. There are lots of good examples, courses, lessons, blogs, and clever people who can answer questions.
However you will find yourself missing out on a lot of easy wins - particularly in cases where you read some Objective-C code and want to know how to translate it into Swift for your projects.
Objective-C is easy enough to learn - if you are going to be mostly just reading it. If you are writing it, of course, there are some tough things.
Either way you absolutely cannot go wrong and you will end up knowing both very well within a year.
...though his invention worked superbly -- his theory was a crock of sewage from beginning to end. -- Vernor Vinge, "The Peace War"