Lost Private Keys question

Hello all,

I'm researching solutions for governments who want to use the Ethereum blockchain for various types of applications, such as Land Registry, VAT tracking, and possibly minting their own tokens on top the the blockchain. One of the biggest problems that I can see is the consequences of a government losing control of their private keys. This would seem like a showstopper vulnerability for many risk-averse government ministries.

Can anybody suggest any possible solutions that might satisfy governments that this risk can be mitigated or even eliminated?

Thanks