How to identify myself
You can use a digital certificate/DNIe or Cl@ve, either Cl@ve permanent or Cl@ve PIN, see how you can register. Please note that an advanced level registration grants security level 2 with PIN and security level 3 with Cl@ve Permanent, while a basic registration grants security level 1.
The Social Security has procedures that can be accessed by verifying your personal details Vía SMS, but for this you need to have communicated your mobile phone number.
You can also carry out some procedures Sin identificación.