I'd love to have a secure private method to delay sharing information, but this project isn't what I'm looking for.

For a while now, I've been thinking about a service that provides PGP encryption and allows to decrypt it only after a certain Bitcoin block was mined. The service can for instance create 2 million different PGP signatures, which is enough to last 30 years. The user first encrypts a text with his own PGP keys, then with the service's keys (and if needed with his own keys again). This ensures the service never knows your data.
Then, you give the encrypted data to someone, who can decrypt the data after a certain Bitcoin block has been mined.

The flaw in this system is of course the centralized service: if it disappears, decryption is no longer possible. And if it provides the keys too early, decryption can happen before the Bitcoin block was mined.
The first problem can be mitigated by having several (trusted) services that share and store the same (2 million) PGP signatures. If one of them disappears, another takes over. But this increases the risk of leaking the keys. So this idea doesn't work either, but if someone can improved upon it, that would be great!