> The link between a person and the identity number is established through the civil registry and through identity documents and secondarily through the widespread use of the number in various contacts with authorities, businesses etc. They are necessary for personal service at banks, authorities, health care and other services which use the personal identity number. Most people are familiar with their full number and those of their children without hesitation. Personal identity numbers of individuals are openly available from the Swedish tax authorities to anyone who asks (over phone, letter, over the desk, but not over the internet), according to the Swedish principle of freedom of information. Redistribution of these numbers using computers is, however, governed by the law of personal details, an implementation of the Data Protection Directive.

https://en.wikipedia.org/wiki/Personal_identity_number_(Swed...

Then 2FA through BankID, with a chain of trust started with the KYC of your bank. No SMS, "state something only you know" or similarly awful methods.

https://en.wikipedia.org/wiki/BankID

That keeping secret your SSN is a thing is something that mostly affects the US.

They are from a country where SSN where its a shitty master password for their life, and was wondering if Russia was the same way or if it was potentially implemented better.

That's us. It's our word. You can pry it from our cold dead lips.