Посмотрел как обстоят дела с IPsec в DragonflyBSD

IPsec там безопасный. Он просто отсутствует, начисто :-)
Date:   2018-04-21 23:26:37 +0200

    Remove IPsec and related code from the system.

    It was unmaintained ever since we inherited it from FreeBSD 4.8.

    In fact, we had two implementations from that time: IPSEC and FAST_IPSEC.
    FAST_IPSEC is the implementation to which FreeBSD has moved since, but
    it didn't even build in DragonFly.