EternityWall shows message in the Bitcoin blockchain. Due to economic incentives, the Bitcoin blockchain is the nearest thing to digital eternity.
A message is a transaction with an OP_RETURN output containing valid utf-8 starting with characters "EW".
All dates are referred to the block timestamp containing the transaction and are in UTC.
How to write a message with Bitcoin Core.
You can use electrum too, but remember to start with hex `4557` (EW).
Built with blocks iterator.