Ireland, like the UK, has a system of Prize Bonds that work exactly like this, administered by the state. The expected return on them is actually quite competitive, depending on your tax situation.

Everyone here seems to have got a present of €20 Prize Bonds for a 10th birthday from an aunt or grandmother, yet people from outside are always surprised that such a product can exist.

My return on premium bonds this year (so far) is roughly 3.2% annualised - it's not bad considering that it's tax free, and secured by the government