[CLAIMED!] Bounty: 0.25 BTC. Find the Bitcoins hidden in plain sight.

[sgravina]

That is exactly it. Bends the mind a little bit the first time you here of such one-way functions. But the math is solid.

It is cool.  You need a function that is destructive.  The private key to address function must lose information so that it is not reversible.

Real world examples are plentiful.  You can generate a unique hand from every person, but you can't generate a unique person from any hand.

Sam

[1714175838]

1714175838

[1714175838]

1714175838

[1714175838]

1714175838

[oOoOo]

store that on "the cloud" somewhere if you're worried about losing it.

While I appreciate your point, I'll have to disagee.
The idea of "storing your wallet in the cloud" relies heavily on assumptions about current and/or future bitcoin users, which might not be met.

First of all, your idea assumes that a user can access the "cloud" or the net at anytime, anywhere at their will. Besides that, it also assumes that the user lives in a place with established infrastructure and reliable net access. We can go a step further and also assume that a cloud remains stable and the provider doesn't go bankrupt etc.

Encrypting the wallet like you describe is certainly the right choice for a number of users however, it also introduces additional layers, complexity and potential points of failure.

Having a private key stored in "my brain" and nowhere else gives one peace of mind in a way no other option can.
.

[brendio]

I thought I'd give back to the community for the free 0.0785 BTC I got mucking around in python and have uploaded the source from my python script to github:
https://github.com/brendio/convertphrase

Note, that I don't really know what I'm doing, so use with care. It took me a while to work out how to use github and I'm still not sure I understand it.

[MrJoshua]

Step-by-step guide to claiming coins, easy mode:

Step 1: Create a new bitcoin wallet.
Start bitcoin with a fresh wallet to keep from polluting your current wallet with these addresses. You can do this by temporarily moving your wallet.dat out of your bitcoin data directory, or by making bitcoin use a new data directory. The step is optional but highly recommended.

Step 2: Hash the string using SHA-256 to get the hex private key.
Go to http://www.xorbin.com/tools/sha256-hash-calculator and enter the string. For example, "Damnesia" gives "58c00ef49f161ac94e40cde5106227e09a6dc1840cf601c877b48d9ccc7ebdbe". This is your private key in hexadecimal form.

Step 3: Convert the hex to base58 bitcoin private key format.
Go to http://blockexplorer.com/q/hashtoaddress/x/80 replacing "x" with the hex private key. This tells BBE to encode a bitcoin address of version 80, which is used for private keys. For our example above, we'd go to http://blockexplorer.com/q/hashtoaddress/58c00ef49f161ac94e40cde5106227e09a6dc1840cf601c877b48d9ccc7ebdbe/80 . This gives us the encoded private key of "5JVNazqC4JucAHUeRLhcqrbGFAro2CySd2ptDaDnPe18G9tmuAs".

Step 4: Import the private key into your bitcoin wallet.
If you can build or obtain a copy of bitcoin with sipa's importwallet, start bitcoind (or bitcoin -server) and run "bitcoin importkey y" where y is the base58-encoded private we just created. Now just wait for it to finish scanning the block chain for transactions. If you can't get a patched client, get Python and pywallet. Stop bitcoin altogether and run "python pywallet.py --importprivkey=y" where y is the base58-encoded private key. Run bitcoin -rescan.

Step 5: Send the coins to your main wallet.
Send yourself the coins so nobody else can claim them. Once you get a confirmation or two, the coins are yours and you can close bitcoin and switch back to your primary wallet. Have fun!

Is it possible to do step 3 with openssl on the command line?
(step 2 is 'echo -n "Damnesia" | openssl dgst -sha256', fyi)

How can I get a valid address from this private key with openssl without loading the bitcoin client?

[EricJ2190]

Is it possible to do step 3 with openssl on the command line?

You can use the bash script commands here:
http://forum.bitcoin.org/index.php?topic=2461.msg35749#msg35749

To encode the private key, add those functions and run:
privkey=58c00ef49f161ac94e40cde5106227e09a6dc1840cf601c877b48d9ccc7ebdbe
EncodeBase58 "80$privkey$(checksum "80$privkey")" && echo

[casascius]

How can I get a valid address from this private key with openssl without loading the bitcoin client?

If you use Windows I have published a program that does this

[MrJoshua]

How can I get a valid address from this private key with openssl without loading the bitcoin client?

If you use Windows I have published a program that does this

No I don't use Windows, and I'm trying to do it with built in unix commands.

Being able to create a valid wallet and receive bitcoins entirely offline with tools you already have installed seems like a pretty big deal.

j

[Edit:]

P.S. Plus it seems that if this is true, then "over the phone" bitcoin transactions should be possible in the future. 

[casascius]

How can I get a valid address from this private key with openssl without loading the bitcoin client?

If you use Windows I have published a program that does this

No I don't use Windows, and I'm trying to do it with built in unix commands.

Being able to create a valid wallet and receive bitcoins entirely offline with tools you already have installed seems like a pretty big deal.

j

[Edit:]

P.S. Plus it seems that if this is true, then "over the phone" bitcoin transactions should be possible in the future. 

Search on the forums for a shell script called "BOTG" ("Bitcoins Off The Grid").  Someone has already put together such a thing that uses OpenSSL to do the key work.

[Joric]

relevant http://bitcointools.appspot.com

[brendio]

relevant http://bitcointools.appspot.com

Nice! Doesn't like the Chinese characters though.

[oOoOo]

relevant http://bitcointools.appspot.com

Is this trustworthy? How do I know the private keys aren't secretly stored on the server?
.

[casascius]

relevant http://bitcointools.appspot.com

Is this trustworthy? How do I know the private keys aren't secretly stored on the server?
.

You can't.  I wouldn't have assumed it was meant to secure your 25000 BTC long-term, it's not even using HTTPS.  Looks more like proof of concept to me.  The value is there though, in that once the utility is realized by many, hopefully the feature will make it into the bitcoin client itself, then trust won't be quite an issue.

[Jaagu]

Who's code is http://bitcointools.appspot.com?

Is it your's, casascius, or Joric's?

Where can I get the source code?

[racerguy]

This is a bad idea, I've searched the sha256 hashes of a number of words on google and someones already done it and made it public.

[coretechs]

The easiest safe way I've found so far is through the http://bitaddress.org script.  You can save a local copy and run it to generate the private keys on a disconnected PC + whatever other security measures you deem necessary.