Believe those who are seeking the truth. Doubt those who find it. Andre Gide

Friday, December 30, 2016

Can the blockchain kill fake news?

Not actually fake news, but still good for a laugh.
Bloomberg View columnist Megan McArdle has an interesting article on fake news: Fact-Checking's Infinite Regress Problem. Fake news constitutes blocks of information fabricated either wholly or in part from falsehoods to serve a political end. It is an act of commission, as opposed to a related act of omission: reporting blocks of true information chosen selectively to serve a political end.

A natural response to the problem of fake news is the emergence of fact-checkers. But on what basis are these elected or self-appointed fact-checkers to be trusted? Who will guard the guardians? The solution cannot be to appoint another layer of super-fact-checkers, since this process results in an infinite regress. Ultimately, the solution will have to reside in an answer like: "The guarded must guard the guardians."

Fake news--or fake history, for that matter--is not something new. Every society is built on a store of publicly accessible information--a shared history--that evolves over time. But who is assigned write-privileges to this public ledger and how can they be trusted? How can we be sure that Caesar, for example, didn't fabricate much of what is recorded in his Commentaries?

This the problem with public ledgers where everyone has a write-privilege, as we do with the Internet. But the problem is an ancient one. In small social groups, individuals sometimes spread fake news about others or themselves. Whether this information becomes part of the group's shared history may at times depend more on its truthiness than its truthfulness. And false rumors sometimes do destroy individual reputations. A society that cannot guard against individuals freely rewriting its history for personal/political gain at the expense of the community is almost surely doomed to fail. This is not to say that societies cannot function if they rely on a shared history consisting of fake news. Indeed, they may even flourish if fake news takes the form of (say) nation-founding myths designed to promote social cohesion.

You might be wondering what any of this has to do with blockchain. Well, a blockchain is simply a shared (distributed) database (history) where the database is updated and kept secure through some communal consensus algorithm. In this piece "Why the Blockchain should be familiar to you" I argue that blockchain technology has been around for a long time. Unfortunately, there are limitations to what a distributed network of human brains talking to each other through traditional methods can accomplish as communities grow larger. But recent advancements in our brain power (computers) and communications technologies (Internet) have now made a global blockchain possible. This is exactly what Bitcoin has accomplished.
And so, as 2016 comes to a close, I put forth a whimsical question. Can blockchain (somehow) kill fake news? No, I don't think so. Well, maybe yes, in some circumstances. (Did I mention that I'm an economist?)

The answer depends on what parts of our shared history we can expect to manage through a computer-based blockchain (and on the details of the consensus protocol). The Bitcoin blockchain appears to have solved the fake news problem for its particular application (essentially, debiting/crediting money accounts--though broader applications appear possible). Might the same principles be used to manage the database at, say, Wikipedia (see How Wikipedia Really Works: An Insider's Wry, Brave Account)?

Ultimately, I'm afraid that the fundamental problem with fake news is not that we don't have the technology to prevent it. The problem seems more deeply rooted in the natural (if unbecoming) human trait of preferring truthiness over truth, especially if truthiness salves where the truth might hurt. I'm not sure there's a solution to this problem apart from trying to instill in ourselves these good Roman virtues (veritas and aequitas, in particular).

Happy New Year everyone! Wishing you all the best for 2017.

PS. Just came across this interesting piece: Can Geeks Defeat Lies? Thoughts on a Fresh New Approach to Dealing with Online Errors, Misrepresentations, and Quackery.


  1. I guess the obvious problem is that the financial blockchain is a record of clear discrete events that either happened or didn't. The news (or history) blockchain would be attempting to record events of a much less clear nature. Interesting regardless.

  2. "The problem seems more deeply rooted in the natural...human trait of preferring truthiness over truth, especially if truthiness salves where the truth might hurt."

    We don't have to go back to Caesar to talk about "write privileges" and the trustworthiness of history. We have the election of 2016 and, because of its result, the election of 1876.

    By percentages, Hillary Clinton's popular vote margin over Donald Trump was the largest since Samuel Tilden's quarter-million-plus margin over Rutherford Hayes in 1876. Unlike Trump, however, Hayes also trailed in the electoral vote. Since Hayes was behind by both measures, how then did he become president?

    The answer stunned me when I heard it for the first time on the Rachel Maddow Show a couple of days after November 8th.

    Tilden led 184-165 in the Electoral College, but there were 20 disputed electoral votes: all those of Florida, Louisiana and South Carolina, and, oddly, one electoral vote from Oregon. All 20 of those votes ultimately went to the Republican, Hayes, over the Democrat, Tilden (who, of course, handily won the popular vote and led in the undisputed electoral vote).

    The Democrats agreed to give the presidency to Hayes on the condition that the federal government withdraw the occupying Union troops from the South. With that agreement, the Democrats effectively nullified the Emancipation Proclamation and sentenced America's blacks to almost another century of oppression (an oppression that continues to this day, this time at the hands of the Republican Party, with its relentless imposition of voting restrictions).

    I'm an American History major. Never, in any high school or college textbook that I read, were those facts made clear. It was always presented as a "disputed" election, but the resolution of that dispute was never spelled out. The commission of a huge historical sin was glossed over as if it never happened.

    But it did happen: it lives with us to this day, and it will live with us for decades to come.

    1. Clarifying the opening sentence of the 3rd paragraph: By percentages, Hillary Clinton's popular vote margin over Donald Trump was the largest *for a losing candidate* since Samuel Tilden's quarter-million-plus margin over Rutherford Hayes in 1876.

  3. I would expect the consensus protocol to be more elaborate, but this seems like a good idea to me.

  4. Ultimately defense against fake news has to rely on Lincoln's rule of truth: "You can fool some of the people all of the time, and all of the people some of the time, but not all of the people all of the time." But there's what you might call Gingrich's counterexample: in a democracy you just need to fool 50% of the people plus one and you win. The Byzantine Generals protocol embodied by the blockchain has the same defect, called "the 51 percent attack". A group that controls a majority of the transaction validation resources (e.g. Bitcoin miners) can take over the entire system.

    In the natural sciences, we believe that nature is the truth, and if your experiments give you different results from my experiments, then one or both of us is goofing up somehow, but the truth of the phenomenon that we're studying remains unchanged (up to Heisenberg/Born quantum uncertainty).

    But there are ideologies that privilege their own stories ("the truth that sets men free") ahead of natural truth. Such groups could take control of 51% of the blockchain verification or any other fact-checking system and enforce "fake news" statements. As King Canute legendarily demonstrated with his command for the tide to stop advancing, those whose truth is inconsistent with nature's will eventually drown. This may take a long time, though.

  5. Blockchain applied to news is just more "establishment" trying to appear an authority. This is what people rejected in 2016 because they realised the content of the news (the data) was false.
    The news networks don't need more gold plating they need more truth.