Mining Bitcoin with pencil and paper: 0.67 hashes per day

[Drakim]

I'm probably going to do one step wrongly and get laughed at, but here goes:

7 000 000 000 humans * 0.67 hashes per day = 4 690 000 000 hashes per day (or 54282.4074074 per second)

54282H/s would give us a daily profit of: 0.00078760 BTC ($0.30)

So when the evil space aliens conquers the human race, they can put us to good use to generate 30 cents worth of Bitcoins for them every day (not counting human electricity cost aka food).

[kens]

Interesting idea, but I think you plugged 54Ghash/sec into the calculator instead of 54Khash/sec, so you're too high by a factor of a million. So it won't be worthwhile for aliens to put us to work in the Bitcoin mines and you can sleep soundly at night.

[Keyframe]

Unless babies and the elders and the uneducated can do the arithmetic then number is way lower though.

[a1k0n]

The current network hash rate is ~240e15 hashes/second (240 million gigahashes/sec). So 54282 hashes/second as a fraction of the current network hash rate is 226e-15, which would yield approximately 5.65e-12 bitcoins every 10 minutes or 814e-12 per day which at current prices (~$400) would be 325e-9 dollars.

So your estimate of 30 cents a day is wildly optimistic.

[nroets]

For humans to have a chance, the rate at which blocks are added to the chain will need to fall from once every 10 minutes to once every 36 hours (or longer). That will make bitcoin useless for most transactions.

[dubcanada]

Just saying.. but not everyone is as good as everyone else in math.

Also of your 7 billion, I'm not sure how many are mentally incapable of doing such work (maybe they are really old or really young, etc).

[baddox]

Or they could just force us to manufacture and support computers to generate many more Bitcoins for them every day.

[readerrrr]

With the reduced output the difficulty would lower, and we would generate whatever the demand would be.

[userbinator]

Reminds me of Xiaoyun Wang's discovery of MD5 (and other hash functions') collisions, which was allegedly done mostly manually:

http://www.theepochtimes.com/news/7-1-11/50336.html

Given that the output conditions for a Bitcoin hash are essentially a limited form of preimage attack, I wonder if this "human uses properties of hash function to reduce the problem space, lets the machine bruteforce the rest" method could have any advantage. Machines are great at doing operations quickly, but human brains tend to be far better at noticing patterns and using ingenuity.

[brazzy]

This method is how most (if not all) cryptanalytical attacks work.

[bryceneal]

I'm a big fan of Ken Shirriff's blog. If you're interested in learning more about bitcoin I would also recommend reading his post titled "Bitcoins the hard way: Using the raw Bitcoin protocol".

[kanzure]

> "Bitcoins the hard way: Using the raw Bitcoin protocol"

You mean:

http://www.righto.com/2014/02/bitcoins-hard-way-using-raw-bi...

Also this one:

http://www.righto.com/2014/09/mining-bitcoin-with-pencil-and...

[bemmu]

I assume there are mathematician farms where they are no longer born but grown for the purpose of finding any possible ways to cut steps from hashing.

Do the chips still run this plain vanilla sha256 algo, or have they found some steps that can be skipped? Things like not calculating the final steps if you notice that there won't be enough zeroes.

[Taek]

I do pay a lot of attention to these things, and to the best of my knowledge, nobody has considered something like this. I'm not sure it would be possible, but it would make for some interesting hardware level optimizations. There's always a chance that some company has figured something out but is keeping it secret to maintain a margin over their competitors.

[tejon]

I once calculated the Mandelbrot set on graph paper. This article makes me feel slightly less dorky. :)

[kleer001]

Super cool! Did you know about the Monk who did that hundreds of years ago? Except it was a hoax.

[Totient]

Hmm... I kind of want to figure out a way to make CAPTCHA-coin work now. Cryptocurrency mining for the people!

I just can't think of a good way to generate CAPTCHAs (or something similar) from a block in a fashion that would give human beings a significant edge over computers.

[physPop]

This is really interesting! I'm tempted to borrow this and use it as a lecture for my intro CS students.

[userbinator]

I agree; it's a great demonstration that machines, despite being many orders of magnitude faster, are capable of only the same types of very simple operations that humans can do.

That is one idea intro CS students certainly should get used to, as I've found that manually executing algorithms is good for debugging and learning too.

[ing33k]

"The SHA-256 algorithm is surprisingly simple, easy enough to do by hand"

made my day !

[huhtenberg]

I once coded a Turing machine program that multiplied two numbers. It was almost as remarkable as OP's exercise in its sheer uselessness :)

[smikhanov]

Everyone did it! This is a standard assignment project in CS 101.

[gbajson]

Fantastic project! It reminds me huge nanograms (http://en.wikipedia.org/wiki/Nonogram) I used to solve 20 years ago ;)

[pacaro]

This makes me want to reread “Souls in the Great Machine” again

http://www.amazon.com/gp/aw/d/0312872569/

[ck2]

To keep the theme wouldn't you have to submit them by snail mail?

[kang]

This is the first thing I did when trying to hack the blockchain.

Working out any algorithm by hand first (even though you might not complete all the steps) was how we approached learning in college.

[qwerta]

Nerds :-)

We tried to draw Mandelbrot set 'manually' at university. It included some alcohol so napkin with results got lost.

[yzzxy]

Yesterday I encrypted a password I couldn't afford to lost by hand with a one-time pad on paper. It took a long time to XOR all the letters - I probably should have used a WWII-era style alphabet mod 25 or something , but I needed symbols, and ended up just doing hex-ascii.

[Someone]

Did you double-check your result using a different method, or at least after some hours (to prevent you from replaying an erroneous calculation)? A calculation error could be disastrous.

[gojomo]

A fun future alt-coin gimmick could be to arrange for the first N blocks to be pre-mined by pencil & paper – by invited teams, inside a controlled venue, who have to show their work.

[Site]

This is beautiful and quintessentially quixotic.

[cesarb]

This kind of demonstration is not completely useless, it can be used as part of an argument against software patents.

(We did RSA by hand at my university, and RSA is an obviously mathematical algorithm; to this day, I still don't understand how RSA could be patented in the USA.)

[iowai]

I once was an intern in a startup where the founder one day decided we all shall stop using computers one day a week. I could tell a dozen funny stories that arose from it.

You know, it where the golden 90s. Startups did all kind of crazy stuff. Paint their walls pink and what not. We had the wildest parties. The CEO often brought in a bunch of prostitutes and hired well known DJs.

The days of the week with the "no computer" rule slowed down things unbelievably. And has been abandoned after the founder has been kicked out of his own company. To my surprise, it did not kill the company. The company strives on to this day.

[Achshar]

prostitutes? I could actually believe what you said until that point. Making a day computer-free is something a crazy startup CEO would do (I could actually see myself doing it but once a month maybe, definitely not once a week).

[silon3]

It'd be a good idea to have Keyboard only day for UI designers...

[onedev]

Name the company!

[the_duck]

Artisanal bitcoins!

They're 67 quadrillion times more expensive, but they're all natural and locally-sourced.

[Taek]

Dropping a comment here because of all the down votes. I agree with them. I come to HN for interesting and thought provoking articles, or for interesting news. Pen-and-paper mining is awesome and is totally in the spirit of HN, but single word jokes about "organic" and "fair trade" Bitcoins are clever, but HN is just the wrong place for that. I'd much rather read comments about attempts of other types of cryptography on paper, or perhaps some history about paper based crypto, or anything that adds factual or newsworthy value to the article. Jokes are neiter factual or newsworthy, and I feel are out of place here on HN.

Thanks for understanding.

[physPop]

"Organic"