There’s another way to hide secret messages in transactions. Bitcoin has a special type of code called OP_RETURN that allows users to attach messages to transaction outputs. Let’s see if we can find one.
1. Click here to look at a specific transaction.
2. Open up the details and find the part that is of type “OP_RETURN”.
3. Now locate the “SCRIPTPUBKEY (ASM)” field. See the “OP_RETURN OP_PUSHBYTES_33" part? These are called opcodes. We’re actually interested in what comes after them.
4. Copy the long string of numbers after “OP_RETURN OP_PUSHBYTES_33” and paste it in the code block.