Yes. For example, if interface Vlanif10 of SwitchA and interface Vlanif20 of SwitchB are on the same network segment, perform these steps to configure OSPF MD5 authentication:

# Configure SwitchA.

<SwitchA> system-view
[SwitchA] interface vlanif 10
[SwitchA-Vlanif10] ospf authentication-mode md5
# Configure SwitchB.
<SwitchB> system-view
[SwitchB] interface vlanif 20
[SwitchB-Vlanif20] ospf authentication-mode md5

I think MD5 is not safe enough.

In any case, it is better than nothing.

hmac-md5?