
The manpage of GnuPG mentions the need for memory page locking.
In fact this is not needed as OpenBSD supports swap file encryption.

You can

- enable memory page locking for non-root users if you set the setuid
  bit for the gpg binary (most likely 'chmod u+s /usr/local/bin/gpg').

- enable swap encryption by setting vm.swapencrypt.enable=1 with
  sysctl(8). This is recommended.

In the latter case you may want to get rid of the misleading 'using
insecure memory' warning. Just put 'no-secmem-warning' to your
~/.gnupg/gpg.conf file or use gpg with the --no-secmem-warning switch.

