Last week’s meeting between South Korean president Moon Jae-in and North Korean leader Kim Jong-un, where the Panmunjom Declaration was signed, was recorder on Ethereum blockchain by 27-year-old South Korean game developer. Most cryptocurrencies allow users to store data on the blockchain, thus Ryu recorded each version of the peace agreement, English and Korean, in a single Ethereum transaction by writing it to the input field of each individual transaction. He paid around $10 in gas fees to store the data on the blockchain.