Google stepped up its game into the use of physical keys as a second form of authentication when it integrated Security Key enforcement support to G Suite last week. It goes to show that the search giant is adamant to launch further advancements in security. With that is a new announcement of the availability of a hosted S/MIME service extending encryption capabilities on Gmail beyond TLS.

"TLS only guarantees to the sender's service that the first hop transmission is encrypted and to the recipient that the last hop was encrypted. But in practice, emails often take many hops (through forwarders, mailing lists, relays, appliances)," Google said. "With hosted S/MIME, the message itself is encrypted. This facilitates secure transit all the way down to the recipient's mailbox."

Google gives its assurance that the availability of S/MIME adds account-level signature authentication, which DKIM failed to offer. For the uninitiated, DKIM only provides domain-based verification. What this means is that those who are to receive emails are assured that incoming emails are from the real sending account -- not from a matching domain. Google adds that messages are in no way going to be tampered with after they are sent.

Google has supported Security Keys since 2014 and while hosting S/MIME, the company is providing users additional identity authentication and verification. This initiative also serves as enhanced protection against phishing.

The company also announced that the availability of S/MIME can extend to mobile devices (iOS and Android), as Security Keys also support Bluetooth Low Energy and pair with devices over the BLE protocol. Last week, Facebook declared the addition of support for physical keys as a second form of authentication, Threat Post reported.

Google, Facebook and other technology providers have for years supported second factors of authentication. What's next for Google users is additional protection for personal accounts, which builds off its partnerships with FIDO Alliance. The FIDO Universal Second Factor authentication has been used internally on Google physical keys, the company said.