Blockchain Is Helping to Circumvent Censorship in China

It’s not all hype—at least this time.

A Chinese-style tiger tries to catch a mouse.
Doris Liou

So far this year, governments around the world, including those of the Democratic Republic of CongoSri Lanka, and Ethiopia, have blocked access to a number of websites and platforms, sparking outcry over restrictions on online freedom of speech and expression. In April, Russia began blocking Telegram, a popular encrypted messaging app—a ban that inspired a protest joined by thousands of people in Moscow later that month. The Telegram block was made possible at least in part by Google and Amazon’s decision in May to implement changes that made it harder to access digital anti-censorship tools. Despite the growing landscape of threats to digital rights and online freedom of speech, however, there are some reasons for hope—and one of them may be blockchain.

Given the constant claims that blockchain is the solution to everything from poverty to corruption, it’s understandable if you’re skeptical. But this is an example of a situation in which it genuinely has potential.

In early April, eight students at China’s prestigious Peking University filed a freedom of information request for the school’s official records on Gao Yan, a student who reported two decades ago that she had been sexually assaulted by a professor and subsequently killed herself. The university refused to disclose further information, but on April 5, a friend of Gao’s shared her story online nonetheless. The exposition of Gao’s case and the university’s role in covering it up sparked outcry, and hundreds across the country called on the university and government to do more to prevent sexual assault and harassment.

In response, censors cracked down on online discussions of the issue. They also swiftly removed from WeChat, a popular Chinese messaging app, an open letter penned by Yue Xin, one of the students behind the freedom of information request. Yue’s letter detailed the intimidation and coercion she had faced from the school and authorities following the submission of the request and highlighted the restrictive nature of speech in China both online and offline.

However, a supporter was able to circumvent speech restrictions on this topic by embedding Yue’s letter into the tamper-proof Ethereum blockchain. Blockchain is an open-source, public, distributed computing technology, which is the basis of the well-known cryptocurrency bitcoin. Ethereum is a public blockchain that hosts the cryptocurrency Ether. The anonymous activists sent themselves zero Ether on the platform and embedded the text of Yue’s open letter in the transaction’s metadata. Transactions on blockchain are irreversible, so the information cannot be altered. Furthermore, transactions generate distributed copies of themselves within the network, which ensured that Yue’s letter would be permanently documented in the public domain and accessible to any user who looked the transaction up. However, because communication is not currently a primary use case of blockchain, accessing this transaction data is more difficult than on communications-focused platforms such as social media. In response, students from universities across the country similarly embedded messages in their transaction descriptions, therefore enabling for unrestricted and free conversation on the issue to take place.

The emergence of this tactic for circumventing censorship comes at a critical time. In May, a security update to Google’s and Amazon’s network architectures ended a popular practice known as domain fronting. Domain fronting was made possible by a “quirk” in a platform’s software stack that enabled external services and tools to disguise their traffic as the traffic of a larger website, such as Google. Because governments are typically reluctant to block these larger platforms, smaller anti-censorship platforms were able to circumvent state- or national-level blocks on their services by disguising their operations as those of larger companies. However, Amazon and Google decided to put an end to this unintended feature because it could also be used to hide malicious activity and therefore posed a security concern.

Although the fear is understandable, domain fronting was a practice that many anti-censorship tools and platforms such as Tor, GreatFire, Telegram, and Signal had previously used. It enabled their users, who include activists, journalists, and human rights defenders in countries such as China, Ethiopia, and Cameroon to circumvent barriers to accessing the open internet and exercising free speech around the world. The emergence of a potential blockchain solution in this space is timely and much needed to fill the void left by the halting of domain fronting.

But blockchain is not a perfect solution here—far from it. Since blockchain is not currently commonly used or understood as a communications or digital rights service, the student protest letter in China did not garner the same level of virality that it would likely have achieved on social media. In addition, after the letter was embedded in the Ethereum blockchain, WeChat prevented users from accessing the blockchain transaction page on etherscan.io and therefore hindered access to the letter and its responses, although it was accessible on other, mostly smaller platforms. In this case, activists were able to circumvent some of the WeChat censorship by flipping images of the letter upside down. Nevertheless, this is a major challenge to using blockchain to circumvent censors at a greater scale. In return, it is likely that activists will be able to find ways to side-step these obstacles. But other challenges will crop up. If blockchain is to be a sustainable solution in this space, activists and organizations like Civil and Zappl that are working in the blockchain, free expression, and anti-censorship spaces will have to be nimble—because the development of tools for both censorship and fighting censorship is an ongoing cat-and-mouse game.