You would assume that since Google search doesn't even check to make sure the HTTPS is valid for your search ranking boost that Google also doesn't check to see the level of security for a domain name in search. So adding security features such as DNSSEC, DKIM or SPF does not play a role in search either.
Google's John Mueller confirmed so on Twitter:
Not for search at least.
— John ☆.o(≧▽≦)o.☆ (@JohnMu) February 11, 2018
DNSSEC:
The Domain Name System Security Extensions (DNSSEC) is a suite of Internet Engineering Task Force (IETF) specifications for securing certain kinds of information provided by the Domain Name System (DNS) as used on Internet Protocol (IP) networks
DKIM:
DomainKeys Identified Mail (DKIM) lets an organization take responsibility for a message that is in transit. The organization is a handler of the message, either as its originator or as an intermediary. Their reputation is the basis for evaluating whether to trust the message for further handling, such as delivery.
SPF:
Sender Policy Framework (SPF) is a simple email-validation system designed to detect email spoofing by providing a mechanism to allow receiving mail exchangers to check that incoming mail from a domain comes from a host authorized by that domain's administrators.
When my company sets up a domain name configuration for a client, we set these all up. But not for ranking in Google, for the other reasons laid out around security, better deliverability and more.
Forum discussion at Twitter.
