For long-term storage, it's best to use full node wallets. For bitcoin, this is Bitcoin core, for ripple, find an official wallet too.
With this approach, your coins will be 100% safe.
Only it is probably worth using a separate computer for these purposes.
Thank you everyone....
Say for eth, what full node wallet is there. I tried searching for the "native" full node client but was not too lucky. Any chance you can point me in the right direction?