Is there alternative to patent system for anyone who just want to have a prove that he was first (just in case)? Something like store patent in blockchain.
The technology exists: trusted timestamping and commitment schemes are well-understood. But does it matter in today's adversarial patent environment? You still need to actually appeal the thing, which takes time and lawyers.
Publish. Post to a blog and get it into the wayback machine, nobody will ever be able to patent it then.