Throw a Rock, It Flies in an Arc

“When Karl Marx began to truly study capitalism, he realized one thing that many others, even over the hundreds of years since, have failed to see. When people act within capitalism, it is only as personifications of economic categories. Do you think that is true?”

The man winced internally. Satoshi was here to describe some great economic innovation, and he was going to start with Marx? What could he hope to glean from the greatest failed economist of the 19th century?

“Mr. Tsuyata?”

Katsuhiro Tsuyata adjusted his collar.

“Mr. Nakamoto, I am not an economist. Nor am I a historian.”

Satoshi smiled that sinister joyless smile of his, his eyes still locked with Katsuhiro’s. A small van buzzed past in the street below, the bright summer afternoon sun glinting off chrome wing mirrors into the second-floor window of the squat two story akiya, humming north through the outskirts of Kyoto to the city centre.

“I hope that is true. Economists and historians are always too late. The owl of minerva flies only after dark, you know.”

“I’m afraid I don’t see what you’re getting at, Mr. Nakamoto.”

Katsuhiro wished Satoshi would simply tell him what was going on. He wished they didn’t have to meet in this breezy, run-down abandoned house, so far from his apartment. Most of all, he wished Satoshi would stop smiling like that.

“Do you think I am wasting your time, Katsuhiro?”

“Mr. Nakamoto” he pushed the familiarity away “I think no such thing. You seem to think this is of the utmost importance, and you tend to be correct about these matters.”

He paused, waiting for a response, but getting none.

“Nevertheless, I would appreciate some clarity.”

Satoshi smiled again.

“You flatter me, Mr. Tsuyata. Well, I will stop keeping you in suspense. You see, I have been paying close attention to the current global economic situation, and it seems to be particularly unstable. Perhaps it will never be quite as stable again.”

Katsuhiro thought this was an understatement. You didn’t have to be paying particularly close attention, or even really any attention at all, to understand that the ‘global economic situation’ was ‘particularly unstable’. The American financial system was in the midst of total collapse.

“Banks, Mr. Tsuyata. Ridiculous institutions, don’t you think? When it was difficult to keep track of large sums money, as trade increased across the globe, perhaps worthwhile. Money, the oldest institution in the world - as old as grain, Mr. Tsuyata - far older than banks, do you think now we still need them? In this day and age, of computers, of the internet, of a precise mathematical monetary guarantee, with no need for a bank, no need for trust, in such short supply these days - behind any of it?”

Satoshi was now leaning forward, over the edge of the table at which they sat. His hands still sat on his lap, below the edge, giving him the poise of a man in a straightjacket, straining to escape his chair. A group of youth passed by in the street below, chattering and laughing.

“This is the innovation, Mr. Tsuyata. Decentralized currency. It is called ‘Bitcoin’” - He pronounced the word in perfect, unaccented English - “totally public, yet totally anonymous, and utterly impossible to defraud.”

“And how does this work?”

Satoshi waved his hand dismissively.

“No matter. I do not think you would understand it - I do not mean that as an insult, Mr. Tsuyata. I do not think many people will understand it. More importantly, I do not think it matters.”

“I would simply like to have some idea that this is as good as you say, Mr. Nakamoto.”

Satoshi grumbled.

“I want you, Mr. Tsuyata, to imagine a currency where all transactions are constantly kept track of on a public list. Every interested party, that is to say all those holding the currency, has a personal copy of the list. Let us say that I want to pay you a small sum, 5 bitcoins - I add this transaction to my list - attaching a signature unique to both the transaction and myself - and I disseminate the transaction, so that everyone knows this money has changed hands. Although, Mr. Tsuyata, in this case you may note that it is as if there is no currency at all - only a collection of lists, keeping track of payments.”

“Go on.”

“Now, these individual lists - we call them blocks, Mr. Tsuyata - have only a limited number of transactions on them. Certain people, those willing to put their own computational power towards this effort - not as volunteers, mind you, they are rewarded for their efforts by new Bitcoin for each block - will collate these transactions, and attach to each block a number - a very special number, Mr. Tsuyata. For this number will ensure that when passed through a relatively simple but utterly irreversible function, the whole block will return a new binary number, and the beginning of this number, which we call a hash, will be a long collection of zeros. Changing any aspect of the block will change this number - only attainable by random, guess-and-check computation, but incredibly easy to check once found - and change it completely.”

Katsuhiro was beginning to feel that Satoshi had been right. He was struggling to understand, and he could see Satoshi straining to simplify the process, drumming his fingers impatiently on the table, like a world-class sprinter jogging along beside a wheezing friend on a daily run.

“You see, the validity of the transaction is guaranteed not by a central authority but by the exact opposite - by the publicity of the validation process. Each block contains the hash of the block before it, chaining them together. To change an earlier transaction would not only require finding new numbers for every block, to ensure every hash was correct, but also to constantly be producing new blocks with the old false hash. By making block creation a public process, the computational power required becomes totally feasible, and fraud becomes nearly impossible. One single party would have to have over half of the total computing power committed to block creation to even stand a chance at this. This process, what we call a ‘proof of work’ - that is the mathematical guarantee.”

Katsuhiro nodded.

“All of which is to say, Mr. Tsuyata, you will simply have to take my word for it.”

“And you believe it will change the world?”

Satoshi abruptly stood up, walking to the window with an unnerving smoothness of gait. The dappled sunlight cast spots across his pale skin and white shirt, and Katsuhiro thought for a moment of a cheetah moving gracefully through the grass of the African savannah. Humans had first emerged on those same plains, and, though the cheetah was faster, more athletic, more deadly - humanity had been the species to come out on top.

He spoke without looking at Katsuhiro.

“I do not believe a thing. I do not need to. I am simply an agent of history, of iron laws. When you throw a rock, it flies in an arc.”

He turned, a glint in his eyes, but his face betraying no emotion. Perhaps it had only been the sun.

“Do you believe in that, Mr. Tsuyata?”