When Bhutan’s state fund moved 175 Bitcoin worth $11.85 million in early March 2026, that transaction produced a string of letters and numbers — a transaction ID, or TXID — that permanently records every detail of the transfer on the Bitcoin blockchain. The sender address, the receiver address, the amount, the timestamp, the network fee: all of it is encoded in a format that anyone with a blockchain explorer can retrieve, at any time, for as long as the Bitcoin network exists. This is not a feature that most cryptocurrency participants think about on a daily basis. It is, however, one of the most consequential properties of public blockchain…