Invisible Conversations in the Blockchain World: Exploring Messages on the Bitcoin Network

In recent years, security incidents in the blockchain field have been frequent, and on-chain messages have gradually attracted attention as a unique communication method. In an anonymous environment, this approach provides an effective way to establish initial dialogues and lays the foundation for subsequent fund recovery. This article will focus on the on-chain messaging mechanism of the Bitcoin network, detailing its implementation methods and application scenarios.

The Core of Bitcoin On-Chain Messaging: OP_RETURN Instruction

The Bitcoin network supports on-chain messaging, and its core tool is the OP_RETURN instruction. This instruction allows users to embed 80 bytes of custom data within a transaction. This portion of data does not participate in transaction validation and does not affect the UTXO state; it is purely used for recording information and is permanently stored on the blockchain.

How to Use OP_RETURN for On-Chain Messaging

1. Encode the content of the message

First, you need to convert the text information into hexadecimal format (HEX). For example, the HEX conversion of "This is a test." is: 54686973206973206120746573742e. You can use online tools or Python scripts to complete the conversion. Note that the message content must be less than 160 hexadecimal characters (80 bytes); if it exceeds, you need to simplify the information or send it in multiple parts.

2. Build transactions with OP_RETURN

Use a Bitcoin wallet or tool that supports custom transactions to create a transaction containing an OP_RETURN output. For example, with Bitcoin Core, you can manually add an OP_RETURN output using the createrawtransaction command. Some mobile wallets also offer advanced modes that allow direct input of OP_RETURN data.

3. Broadcast Transaction

Broadcast the signed transaction through the Bitcoin network. Since OP_RETURN transactions do not involve actual transfers, sufficient miner fees must be included to ensure the transaction is processed.

4. View message content

After the transaction is confirmed, it can be viewed through a block explorer. Most explorers will automatically decode the hexadecimal data of OP_RETURN into readable text.

Practical Applications of OP_RETURN

In security incidents, OP_RETURN is used for various purposes:

1. Negotiation tools: The attacker may use it to express the intention to return funds, or the project team and security team may attempt to establish contact with the attacker.

2. Address Tagging: There have been users who used OP_RETURN to mark nearly 1000 addresses suspected to be related to specific institutions, while intentionally burning a large amount of Bitcoin to attract attention.

Precautions

Although on-chain messaging provides convenience for communication in an anonymous environment, users still need to remain vigilant. Attackers may use this method to guide victims to malicious links or execute dangerous operations. In the event of a security incident, it is recommended to seek assistance from a professional security team immediately to increase the chances of fund recovery.

Finally, whether it is individual users or project parties, they should continuously strengthen their security awareness, take comprehensive protective measures, and reduce the risk of becoming a target of attacks. In the rapidly developing field of Blockchain, security is always the primary consideration.