This is what I use when logging in to the state run bookmaker/lottery company in Norway. Works great. I just type in my SSN and I will get a notification on my iPhone. The solution is delivered by Buypass[0].
My bank, Skandiabanken,sends an ordinary SMS message so it works with any mobile phone including dumb phones. To compromise it someone would have to know my personnummer and steal my mobile. Skandiabanken also gives me a scratch card one time pad so that I can log in without the mobile, the web page asks for the n-th number from the card.
[0] https://www.buypass.com/?_ga=1.237154944.1017563517.14669318...