More reliable than Telegram: using blockchain for messaging

The ability to exchange text messages on the blockchain has saved two projects in the last couple of weeks alone: the KiloEx exchange and the zkSync protocol. The developers sent messages to hackers on the Ethereum network and offered a deal where the hackers would return 90% of the stolen assets and keep 10% as a reward. And it worked. GetBlock AML Research explains how to send and receive text messages on the blockchain.

Why is this possible

Blockchain is a secure distributed ledger that stores information. Therefore, text user data can be added to transactions in addition to technical information about transfers. Because of the architecture, the data must be represented as a 16-digit code (HEX).

A text message was contained in the first transaction, which was conducted by the mythical Satoshi Nakamoto on January 3, 2009. The message contained the headline from The Times reflecting the dire state of the banking system: “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks”.

The first message in bitcoin’s genesis block

How to send a message on the bitcoin blockchain

The integration of user data into bitcoin transactions is done using the OP_RETURN method. It can be used to add a text message weighing no more than 80 bytes. Just like technical data, a text message sent using the OP_RETURN method will be stored on the blockchain forever.

To send a message on the blockchain, you must first convert the text to hexadecimal code. This can be done using free services on the internet. A single transaction can contain a maximum of 160 characters (80 bytes). To transmit a longer message, it can be split into several transactions.

Converting the text “GetBlock AML Research” into a 16-digit code

The next step is to find a wallet that supports working with the OP_RETURN method, for example, imToken. In the transaction window, open advanced settings (the “Advanced” button), enter the 16-digit code in the OP_RETURN field, and confirm the input. Please note that sending a message is just like a regular transaction, it requires payment of a fee.

Sending a message using imToken

You can view the sent message using the blockchain explorer. To do this, you need to enter the transaction ID in it.

The sent message in the GetBlock blockchain explorer

Sending a message on the Ethereum blockchain

Sending messages on the Ethereum blockchain works the same way as on the bitcoin blockchain. The first thing you need to do is to convert the message into hexadecimal format, and then find a wallet that supports entering additional transaction data. For example, you can use the MyCrypto service. In the transaction setup window, paste the encrypted message into the “Data” field. Note that on the Ethereum network, the message must begin with the instruction “0x”.

Sending a message on the Ethereum network using the MyCrypto service

There is a simpler way to send messages on the Ethereum network, through a special Input Data Messages (IDM) service. This service allows you to send text messages without encrypting them beforehand. In the Input Data Messages field, you can immediately enter a test message, and then it will be automatically converted into a 16-digit code.

Sending a message on the Ethereum network using IDM

You need to use the appropriate explorer to view messages on the Ethereum network.

Text message as a 16-digit code in the Etherscan blockchain explorer