Is it permissible to apply for an old age state pension?

Our understanding of pension funds is that it is a combination of interest and qimaar (gambling) according to the Shari’ah. Hence, investing one’s wealth in a pension scheme is impermissible. However, if the pension fund is a government owned fund which renders assistance to the citizens of the country, whether it is without them investing wealth or with them investing wealth (e.g. a percentage of one’s earnings go to the government with the aim of rendering assistance to their citizens in old age), then since the government has taken responsibility of taking care of their citizens, especially when they are old and unable to fend for themselves, it will be permissible for them to apply for it or seek it in any permissible way.

And Allah Ta'ala (الله تعالى) knows best.