Can't upgrade GNUPG?

Solution 1:

GnuPG 1 and 2

First of all, GnuPG 1.4.14 is not really outdated, there are two branches of GnuPG developed at the same time. Also see Are gnupg and gnupg2 compatible with each other?

On Debian and derivated distributions, GnuPG 1 is installed as gpg, whereas GnuPG 2 is installed as gpg2 (but you might need to install the gnupg2 package).

Key Versions

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1

This is not an OpenPGP v1 key, the comment just indicates that GnuPG 1 created it. Both GnuPG 1 and 2 generate OpenPGP v4 keys. You can see what format is actually used by running (no matter whether using gpg or gpg2)

gpg --export [key-id] | gpg --list-packets | head

which will output something like

:public key packet:
    version 4, algo 1, created 1356475387, expires 0

(Not) Building GnuPG on Your own

I strongly recommend not building GnuPG on your own. Apart from verifying sources, you need to regularly recompile to get security updates. Mint Linux already includes a fairly recent version of GnuPG 2 (2.0.22) with all security fixes backported, it should be totally fine sticking with that until a newer distribution will bring a new minor version.