Rumors begun circulating yesterday that the authoritarian communist government of China may take the ultimate step of blocking bitcoin nodes, in effect unleashing a total crackdown.

An alleged document titled “Technical Preplan on Blocking Bitcoin overseas Transaction” is rumored to have been leaked, with its pictures circulating in WeChat and on Weibo by someone with 41,000 followers.

The authenticity of this document can not be confirmed, but seems to have been shared by an insider and apparently an investor from what we can gather based on Sina’s reporting on an article titled “Will the pools be shut down?”

They note Huobi and OKCoin suddenly changed their notices from saying they were to stop CNY trading, with the rest of their business unaffected, to saying they will “stop all virtual currency trading business.”

The executives of Huobi and OKCoin have apparently been banned from leaving the country, with Australia’s Financial Review quoting a mining investor who said they were “preparing for the worst.”

The document, if legitimate, lays out a plan to block bitcoin transactions through throttling or stopping bandwidth connections to bitcoin nodes. According to a translation, it says they are to:

“1. Block accesses to overseas exchanges such as Coinbase, bitfinex, localbitcoins on main egress router, including web access, app access, and API access interfaces.

2. Block access to the Bitcoin seeding nodes on the primary exit router,

3. Through DPI recognition, discard Bitcoin blockchain synching data on main firewall.”

Sipa, BlueMatt and DashJr are Bitcoin Core developers who run seed nodes, helping new nodes to connect to the network. The plan apparently aims to stop such connections, cutting-off China from the rest of the world.

Arguably, connection could still be maintained as just one node, using Tor or VPN, would be sufficient to keep the network synchronized. However, the document says mining pools will be closely monitored and they may:

“Contact local communication administration authority to cut off internet access of mining pool if necessary.”

Chinese entrepreneurs operate huge mining farms, gaining a competitive advantage due to very cheap, if not fully free, hydraulic power.

An untranslated, and apparently unrelated, report by Chinese media on bitcoin’s biggest miner, Bitmain, says they earn $300,000 worth of bitcoin a day.

The context is unclear, but if China did ban bitcoin mining, it would likely affect the entire network as some 80% of the hashrate is concentrated there.

Difficulty, therefore, would likely fall considerably, with block times delayed significantly to the point where the network may become in-operational.

The bitcoin community, thus, would need to decide what measures to take in response. One option may be to hardfork a difficulty decrease in the style of Bitcoin Cash, so lowering it if there have been hours without blocks, or as ethereum does on each block, rather than every two weeks.

Another option would be to fully change Proof of Work, starting from scratch, but that would affect non-China based miners too, who may resit it.

It is probable the bitcoin community would quickly be able to react if such state of emergency was brought on the currency, but it has arguably never happened before, so we do not know.

As such, rather than hoping for the best, all crypto developers may start preparing for the worst, as far as mining is concerned, as this space may face one of the biggest challenge yet, so reminding us once more of the dangers of centralization.