How to Prove a File Existed Before a Certain Date Using Bitcoin (Without Running a Node)
Zeke
The timestamp problem You ship a file. A week later, someone claims they had the same idea first. How do you prove your file existed before theirs? Cryptographic hashes solve "this file is unchanged." They do not solve "this hash existed at this time." For that you need a timestamp that somebody else can verify without trusting you. The two usual answers are a Certificate Authority timestamp (trusts the CA) or a blockchain transaction (costs fees, requires a wallet, requires you to wait for conf