How can I encrypt/decrypt variables in blueprints?.. if its possible of course
There are a couple of solutions on the Marketplace:
Vega Crypto Blueprint Library - https://www.unrealengine.com/marketplace/vega-crypto-blueprint-library
LE Encryption - https://www.unrealengine.com/marketplace/low-entry-encryption
You can also add a C++ class and link your own encryption library or create your own encryption system.
Finally you can use simple text manipulation … dependent on what your requirements are. I own both of the above plugins and I have found the Vega one to match my requirements better.