On average, there about 10 million active sessions a day on Taiwan’s version of reddit, a 25-or-so-year-old bulletin board system called PTT. That’s a respectable number considering Taiwan’s total population is 24 million. But lately the platform has been hit with many of the same problems that have muddied other social media sites—and now, its leaders are taking extreme measures to wipe it clean.

Last month, PTT’s administrators started developing a modified platform that could store data on distributed ledgers—permanent records shared among users themselves. Today, PTT’s servers hum on a National Taiwan University campus in Taipei—where it began as a student project. But this single entity is a clear target for authorities to pressure if they want to censor content.

If data is instead distributed across just enough independent entities, then the risk of censorship is much lower. And there’s another benefit: users would “own” their data and control their own privacy.

Chu Yichen, CEO of BiiLabs (a Taipei-based startup building the backend architecture, said, “it will be difficult” to create. There are three main technical roadblocks to decentralizing social media with distributed ledgers.

Verification

Distributed ledgers are designed so that a computing network must check every new action, or transaction, and gain consensus from nodes on the network that the transaction is correct, before adding it to the ledger.

In the beloved Ethereum blockchain, transactions are grouped into blocks that miners must process and verify before adding whole blocks, one-by-one, to a chain (today, the network can handle about 11 transactions per second). But that delay would make a page take so long to load that a high-traffic platform such as PTT could lose users, Chu said.

BiiLabs is creating an optional version of PTT on top of the public IOTA, an at times controversial alternative to blockchains. Its trick for gaining consensus is supposed to protect it from slowing down as traffic increases. When someone initiates a transaction (for example, a message) and wishes to add it to the ledger, that person must first verify two other transactions before their entry can be added.

Storage

Regardless of its architecture, any network of computing nodes must keep copies of a distributed ledger on hand. And the larger the copies are in size, the larger the nodes’ available storage must be (this month, the size of Bitcoin’s blockchain is about 168 GB). Chu said BiiLabs could only store “a few kilobytes” of data for PTT, such as transaction logs, personal information, and a hash of message content.

The content itself would have to be stored in some yet-to-be-decided decentralized system that can handle many people reading posts at random points in time. It could be that Oyster, a distributed database built on IOTA and Ethereum, fits the bill. Chu said, in any case, it’s still valuable to have a hash on the ledger because you can use it to check for tampering.  

Deletion

Blockchains promise transparency. But privacy rules such as the European Union’s GDPR (which goes into effect on May 25) require personal stuff be deletable on demand. “If we can really erase the data,” Chu said, “then how can [a] distributed ledger be trusted?”

In fact, there is currently no acceptable way to both store data on a ledger and also comply with GDPR. Chu said GDPR’s scope for what qualifies as personal data (“any information relating to an identifiable person who can be directly or indirectly identified in particular by reference to an identifier”) is “too wide.”

A variety of upstart platforms outside of Taiwan, such as Steemit, AKASHA, and Minds are also trying to give users independence from centralized organizations with blockchains. This month, Recode reported that even Facebook made an internal group to explore potential uses for blockchain technology.

Minds CEO Bill Ottman said he views “the push towards decentralization as a gradual process.” His team’s open-source social network, headquartered in Connecticut, runs advertising, crowdfunding payments, and a contribution reward system on Ethereum. But because it couldn’t find solutions that met its needs for traffic, storage, and a backend network with a large enough size to prevent disruption from spam attacks or hackers—for now, all the other data required to run the social media network remains outside of distributed ledgers.