But this means that there is a trusted party involved: the bootstrap nodes. Those might not exist anymore in the future. If they don't, the key cannot be releas

But this means that there is a trusted party involved: the bootstrap nodes. Those might not exist anymore in the future. If they don't, the key cannot be released anymore? In my opinion something like this must not depend on the online status of some nodes. I think, for the black box to be truly trust-less, it must be a `f: Blockchain -> Maybe DecryptionKey`. And then you can provide a specifically crafted blockchain to extract the key...