[Edited to ask more specific question]
I require to encrypt some files with a strong symmetric encryption algorithm - AES256 seems like a good choice - and use GPG for this. I am only using GPG for this symmetric encryption, and I do not presently need it for any other cryptography tasks.
The version of GPG I have is the one that came with this version of Ubuntu - v1.4.16. But I wonder if there could be any future problems/issues with using GPG v2.x to decrypt an AES256 encrypted file that was created by an older GPG v1.4?
If I did upgrade to a newer GPG version - what would be the best way to do the upgrade, for this version of Ubuntu? Would the old gpg version be kept? And could there be any conflicts between the versions to be aware of?
[Re Closure of my question :- Perhaps it could be moved to another StackExchange forum such as SuperUser or Unix/Linux. On reflection Ask Ubuntu was maybe not the best forum to post it to, as its not specific to Ubuntu, that just happens to be the system I am on. I have changed the title.]