Creating permanent uncensorable messages on the Bitcoin blockchain
Tags: Articles, Messaging, Bitcoin, Censorship, Cryptocurrency

One of the most commonly praised features of Bitcoin is the fact that its underlying technology stores immutable information about transactions. When money is sent or received on the Bitcoin blockchain, relevant details are publicly viewable and impervious to change. Less attention, however, is given to the fact that blockchains can also store permanent and uncensorable messages.

Since Bitcoin is not controlled by a single ruling entity and is not vulnerable to a single point of failure, messages stored on its blockchain cannot be censored or deleted. The network is decentralized and maintained by users all over the world who run Bitcoin nodes. As long as there are still nodes out there, everything recorded on the chain will continue to exist in its original form.

Storing hidden clues about Bitcoin’s origin

The first message ever recorded on the Bitcoin blockchain was hidden in its genesis block. When the network went live on January 3rd, 2009, Bitcoin’s anonymous creator stored a cryptic message in the form of hexadecimal characters. When converted, it reads “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks.”

This message is a reference to an article published in The Times on January 3rd, 2009. Since then, physical copies of that day’s paper have sold for exorbitant amounts of money due to its connection to Bitcoin and the cryptocurrency movement as a whole. In addition to serving as a demonstration of how blockchains can store uncensorable communication, the message is also a permanent symbol of Bitcoin’s origins.

While the identity of Bitcoin’s creator(s) — referred to only as “Satoshi Nakamoto” — remains a mystery, the message stored within Bitcoin’s genesis block is a firm indicator of what motivated the digital asset’s creation: the global financial crisis, which shook the public’s faith in major financial institutions.

According to Bitcoin proponents, the crisis also emphasized a need for decentralized methods of trade and spending that are free from the pressures of intermediaries. Thanks to the uncensorable and permanent nature of messages stored on a decentralized blockchain, there will forever be a reminder of the mentality that spawned the Bitcoin movement.

How messages get recorded on the chain

Bitcoin functions through the use of ‘miners’ who lend their device’s resources in order to verify transactions and maintain the network’s integrity. More often than not, it is these miners who store messages on the blockchain in coinbase data — often during notable events. For instance, when Bitcoin’s mining reward halved in 2020, miners immortalized the message “With $2.3T Injection, Fed’s Plan Far Exceeds 2008 Rescue.” This, of course, pays homage to the text stored within the genesis block. It once again serves to emphasize the ethos of the Bitcoin movement as an escape from financial intermediaries.

Notably, coders Dan Kaminsky and Travis Goodspeed encoded a permanent tribute to the late cryptographer Len Sassaman on the Bitcoin blockchain back in 2011. The tribute is one of the most complex messages stored on the chain thus far. Once decoded, it reveals ASCII art of Sassaman alongside a heartfelt tribute.

Yet, it isn’t just miners and coders that are leaving messages on the Bitcoin blockchain. Inputting common phrases on Blockchair brings up a wealth of messages stored within transactions that will now permanently exist on the chain. Searching “Hello” brings up results from miners who have recorded messages in the coinbase and in transactions ostensibly left by everyday users. As Nic Carter called attention to back in 2018, there are even a handful of marriage proposals stored on the Bitcoin blockchain. Today, searching “marry” results in dozens of hits, all of which have been immortalized.

How can I write a message on the Bitcoin network?

Users have several options when it comes to storing messages on the Bitcoin blockchain. One method is to use the OP_RETURN feature when sending a transaction. As HackerNoon observes, this essentially makes the bitcoin you’re sending unspendable but allows you to write up to 160 hexadecimal characters. Alternatively, there are methods which involve encoding messages into various output fields such as the PubKeyHash. Some services simplify the process by utilizing these tricks behind the scenes, in order to offer a more user-friendly experience.

In order to demonstrate how permanent messages can be stored on the chain, we published a little haiku for everyone to enjoy. Using a block explorer, you can hover over the OP_RETURN field to read the message.

When a bitcoin dies,

Should it be interred in bits,

Or SHA-encrypted?

Storing this message forever cost just under two dollars worth of bitcoin. Keep in mind, however, that the bitcoin spent on this transaction will never be accessible by anyone ever again. Should the price of bitcoin spike substantially, the 2,676 satoshis spent on this haiku could one day be worth an uncomfortably large amount of money.

While leaving a single message on the chain is fairly affordable at the current point in time, these methods are prohibitively expensive when it comes to high volumes of communication. This might partially explain why the practice is yet to become widespread.

Other cryptocurrencies, such as Ethereum, make it considerably easier to store messages. Unlike Bitcoin, Ethereum allows for arbitrary storage which makes the process much simpler. Many smart contracts exist which allow users to easily write permanent messages on the Ethereum chain.

The need for censorship resistant messages

Being able to store uncensorable messages has uses that extend far beyond having a permanent indicator of a movement’s history and immortalizing proposals. Notably, WikiLeaks — an organization dedicated to leaking government-sensitive documents — used the Bitcoin blockchain to dispel rumors of their founder’s death. The message “WeRe Fine 8chaN PoSt FAke [sic]” was recorded from a wallet address known to be associated with the organization. This was in direct response to users on message boards who had impersonated WikiLeaks staff and claimed to be in danger.

On a broader scale, censorship-resistant messaging may have important ramifications for freedom of speech and democracy. In many nations around the world, the ability to freely communicate is a luxury that not many are afforded.

Press freedoms as a whole are not unanimously present across the globe. In some parts of the world, dissenting opinions against the government are silenced or even manipulated. As of press time, Reporters Without Borders states that 274 journalists and 116 citizen journalists are imprisoned. With press offices constantly raided and fewer avenues for people to criticize authority in some nations, there is a clear need for ways to communicate that cannot be censored or shut down by the government.

Further, the permanent nature of messages recorded on blockchains could have reaching implications for our future. The adage “history is written by the victors” often rings true. Having permanent firsthand accounts of events could help prevent the truth from being buried in nations that have fallen out of touch with maintaining the rights of their citizens.

Technical and ethical hurdles prevent widespread use

When it comes to Bitcoin’s blockchain in particular, the largest hurdles prohibiting everyday users from recording messages on the chain are the difficulty and cost. Further, there is a case to be argued that messages could theoretically congest the network — though this practice would have to become extremely widespread in order to have any real impact on transaction costs or speeds.

The broader issue lies in the fact that resistance from censorship can, at times, be a double-edged sword. Hate speech can permanently be viewable on the blockchain and illegal and unethical activity can be hidden in blocks.

In 2019, the BBC reported that illegal images of sexual abuse against children were encoded into a Bitcoin fork known as Bitcoin Satoshi Vision (BSV). This action was not tied to the asset itself but rather the fact that virtually anyone can encode messages with very little oversight.

An analysis of content on the Bitcoin blockchain conducted in 2018 did not directly find child abuse within the Bitcoin blockchain at the time. However, it did find apparent links to such content:

“Our analysis reveals more than 1,600 files on the blockchain, over 99% of which are texts or images,” the authors wrote. “Among these files there is clearly objectionable content such as links to child pornography, which is distributed to all Bitcoin participants.”

While a few bad actors do not condemn the network as a whole, the inability to remove problematic and dangerous content is certainly an ethical issue worth considering.

Ultimately, the ability to use blockchains as a way of storing permanent and censorship-resistant messages could prove significantly beneficial in the world today. The challenge lies in addressing the pressing ethical and technical issues that prevent this feature from being utilized to its full potential.