On Block-chains and Bitcoin

A significant breakthrough

Alex Payne quotes Chris Dixon:

The press tends to portray Bitcoin as either a speculative bubble or a scheme for supporting criminal activity. In Silicon Valley, by contrast, Bitcoin is generally viewed as a profound technological breakthrough.

and says:

Now working at vogue venture capital firm Andreessen Horowitz, Dixon is in a fine position to speak for Silicon Valley. But to the extent that the Valley is a placeholder for the technology industry at large, I beg to differ. Bitcoin is “generally viewed” quite differently.

On the merits of Bitcoin as a currency or as a financial asset, technologists are split between optimists, who believe it (or a derivative of it) will be the standard monetary system of the future, and skeptics (such as Payne), who see it as a flawed experiment with troubling political implications.

I don’t wish to comment on that debate, but I believe that, regardless of its usefulness as a financial asset, Bitcoin is a significant technological breakthrough.

The development of Bitcoin is historically important because it solves a problem of computer science that had previously been widely thought to be impossible: it is a decentralized, trustworthy generic transaction store.

I credit the discovery that the Bitcoin technique is more generally useful to Aaron Swartz in his essay Squaring the Triangle, in which he presents an application of the system to secure, decentralized, and human-readable name registration and lookup. (I believe that this essay may to prove be Swartz’s most historically significant work in computing.)

The more general application of the block-chain technique is already happening on a limited scale: Bitcoin’s own block-chain can be used directly as a global information log to prove a document’s existence at a certain time, while Namecoin is an implementation of a similar technique described by Swartz to provide a replacement for DNS.

However, these uses of block-chains still suffer from many of the same problems that Bitcoin itself does: notably, the 51% attack (someone with more than half the CPU power of the network can take control of the block-chain); growing energy consumption and environmental impact as the block-chain grows larger; and the eventual massive size of the block-chain in the years ahead being too large for consumer computers to store (among other miscellaneous weaknesses).

This is why I think alternative crypto-currencies are so interesting. Not so much the trivial ones like Litecoin and Dogecoin, but those that actually make significant improvements to the block-chain algorithm to try to fix these flaws, such as Peercoin, which supplements the proof-of-work system with a ‘proof-of-stake’ to try to reduce energy consumption and solve the 51% problem.

Most importantly of all, the Bitcoin algorithm proves by example that distributed, trustworthy transaction stores are possible, much like Merkle’s Puzzles showed that public-key cryptography is possible (even if the system itself was flawed). I hope Bitcoin-like systems will start getting serious attention from computer scientists working on improvements to the block-chain idea, but I’m also hopeful, now that we know it’s possible, that other decentralized transaction stores will emerge to completely eliminate the problems of the Bitcoin block-chain.