> i've always wondered if there could be a cryptographic solution to this. issuing decryption keys to governments seems rife for abuse, but some sort of multi-party situation where governmental and non-governmental entities have to cooperate (with actual multiparty key material) to perform a decryption authorized by warrants- with said non-governmental agencies acting as a check on usage of those warrants, their frequency and the eventual publication of their usage could be an interesting approach.

I would be willing to consider a solution where you need to have agreement from the UN Security council (maybe just the permanent members) in order to decrypt whatever you want. If you can get those countries to agree, it's probably important.