"deductible" means the amount you have to pay before your insurer will step in. I think a security deposit is more in line with what you're trying to express here. Also, it's not clear whether the network is actually storing the funds (as implied by "...will be released") or if it just keeps an eye on your wallet.
Assuming the latter, suggested rewrite:
>To ensure that they can always be fined, hosts are required to maintain a minimum outstanding balance equal to the maximum possible fine.