This is just a quick post to share a hardened gpg.conf
Usually stored in ~/.gnupg/gpg.conf
personal-cipher-preferences AES256 AES192 AES personal-digest-preferences SHA512 SHA384 SHA256 personal-compress-preferences ZLIB BZIP2 ZIP Uncompressed default-preference-list SHA512 SHA384 SHA256 AES256 AES192 AES ZLIB BZIP2 ZIP Uncompressed cert-digest-algo SHA512 s2k-digest-algo SHA512 s2k-cipher-algo AES256 charset utf-8 fixed-list-mode no-comments no-emit-version keyid-format 0xlong list-options show-uid-validity verify-options show-uid-validity with-fingerprint require-cross-certification use-agent
And I recommend using the key server hkps://keys.openpgp.org
Note that this is not a perfect config and you might add or change things to increase privacy and perhaps security as well. But I tested it to work across Mac, Windows and Linux without issues. Some options might not be supported depending on your version of GPG but this config up there worked across all common platforms for me.