Mental Bitcoin Wallet: I have real bitcoins stored in my head. - page 4.

casascius

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The Casascius 1oz 10BTC Silver Round (w/ Gold B)

Quote from: oOoOo on August 08, 2011, 05:12:28 AM

Quote from: indio007 on August 08, 2011, 01:51:16 AM

So let me get this straight. You can create a private key with a passphrase import it into a wallet. Transfer funds to it and then delete the wallet.dat and recover it by repeating the process?

No. Once you spend your coins from the imported address, the change will be returned to a new address stored in your wallet. If you delete it then, you will lose everything.
What you have to do after the import, is to send the entire remaining amount back to your chosen address in a new transaction.
.

The answer to Indio007's question is "yes in theory", but with the current client, the answer "no" is correct to the extent that the change is likely to go to a newly generated address.

I'd be willing to bet that "pywallet" either does, or could be trivially modified, to fill the unused keypool within wallet.dat with hundreds or thousands of pre-generated addresses that can be derived from the passphrase so the bitcoin client didn't have to.

One passphrase can seed thousands or millions or any number of bitcoin addresses, all of which can be recovered with the same passphrase. If passphrase is "my passphrase", then the first address is based on "my passphrase1" and the second on "my passphrase2", and the millionth on "my passphrase1000000". IIRC, bitcoind only adds keys to the key pool if the number of keys in the pool falls below 100. If you used a deterministic wallet generator to generate a wallet.dat with 10,000 addresses - most of them going into the key pool - you would probably never need to worry about the change going to a new address.

kloinko1n

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Quote from: netrin on August 08, 2011, 08:04:06 AM

Code:

$ echo -n " your mom        " | sha256sum 
888eb5c57140830728b64def5c3d9230f8b7f8d6567814542a92259be16e6007  -

Ok

Question sneakily inserted: Is the ownership of the file blk0001.dat the same as that of the file blkindex.dat?

(I thought I might as well ask that in here as you guys seem to know everything anyway, and my question isn't being answered where I originally posed it.)

netrin

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Activity: 322

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FirstBits: 168Bc

Code:

$ echo -n " your mom        " | sha256sum 
888eb5c57140830728b64def5c3d9230f8b7f8d6567814542a92259be16e6007  -

kloinko1n

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Activity: 406

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Oh, by the way,

Code:

echo your mom | sha256sum

deletes any trailing spaces in "your mom", "your mom ", "your mom " etc.

netrin

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Activity: 322

Merit: 251

FirstBits: 168Bc

I hope alternate clients consider addresses more like accounts (with change returned to the same by default) and move this non-deterministic 'wallet' as an optional part of a greater laundering/anonymity regime. The wallet with newly generated keys is a major source of confusion and the anonymity provided is a joke. Only geeks 'get it' - everyone else has to learn the hard way.

I think it would be wildly cool to pass a slip of paper "The dog barks at midnight 3879273". The ultimate swiss bank account. Or "Congratulations My Son 8360324" or "Bitcoin gold parity. I told you so. Haz Haq Hah! Pennies for the poor."

jackjack

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May Bitcoin be touched by his Noodly Appendage

Quote from: indio007 on August 08, 2011, 01:51:16 AM

So let me get this straight. You can create a private key with a passphrase import it into a wallet. Transfer funds to it and then delete the wallet.dat and recover it by repeating the process?

You don't have to import the key to transfer funds to it, and should not do it

oOoOo

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Quote from: indio007 on August 08, 2011, 01:51:16 AM

So let me get this straight. You can create a private key with a passphrase import it into a wallet. Transfer funds to it and then delete the wallet.dat and recover it by repeating the process?

No. Once you spend your coins from the imported address, the change will be returned to a new address stored in your wallet. If you delete it then, you will lose everything.
What you have to do after the import, is to send the entire remaining amount back to your chosen address in a new transaction.
.

kloinko1n

full member

Activity: 406

Merit: 100

Quote from: netrin on August 08, 2011, 01:31:18 AM

Code:

$ echo your mom | sha256sum 
6e96e45029870a9b08cff2ed6ac840ccde3edce244327cc1bddefa1e555bc81f  -

Quote from: kloinko1n on August 07, 2011, 09:40:06 AM

$ gpg --print-md sha256 < /dev/stdin

which gives the same results as

$ gpg --print-md sha256

Yes, that's much better than my 'solution', thanks!

Quote from: JoelKatz on August 08, 2011, 01:36:52 AM

[snip>
The 'echo' command, by default, puts a newline at the end of its input. You can suppress this behavior with '-n'. (You can do it either way, but this may explain why different tools might given different results.)

Thanks for the addition, very helpful!

ctoon6

sr. member

Activity: 350

Merit: 251

Quote from: benkebab on August 08, 2011, 02:12:01 AM

Hey,
I'm quite new to bitocin so I just wondered: why are they several private keys stored in a wallet.dat? Given what you explained, you only need to know 1 private key, right? Undecided

its soposed to give more anonymity. however i find it pointless, and would rather the client just make a new address when requested.

benkebab

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Activity: 75

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Hey,
I'm quite new to bitocin so I just wondered: why are they several private keys stored in a wallet.dat? Given what you explained, you only need to know 1 private key, right? Undecided

indio007

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Effing sweet! What are the odds of someone using the same private key. I've actually been wondering this for a awhile. What is someone just tries to hoard all possible private keys? Or is it the keypair that matters?

ctoon6

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Quote from: indio007 on August 08, 2011, 01:51:16 AM

So let me get this straight. You can create a private key with a passphrase import it into a wallet. Transfer funds to it and then delete the wallet.dat and recover it by repeating the process?

yep

indio007

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Activity: 224

Merit: 100

So let me get this straight. You can create a private key with a passphrase import it into a wallet. Transfer funds to it and then delete the wallet.dat and recover it by repeating the process?

JoelKatz

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Democracy is vulnerable to a 51% attack.

Quote from: netrin on August 08, 2011, 01:31:18 AM

Code:

$ echo your mom | sha256sum 
6e96e45029870a9b08cff2ed6ac840ccde3edce244327cc1bddefa1e555bc81f  -

The 'echo' command, by default, puts a newline at the end of its input. You can suppress this behavior with '-n'. (You can do it either way, but this may explain why different tools might given different results.)

netrin

sr. member

Activity: 322

Merit: 251

FirstBits: 168Bc

Code:

$ echo your mom | sha256sum 
6e96e45029870a9b08cff2ed6ac840ccde3edce244327cc1bddefa1e555bc81f  -

Quote from: kloinko1n on August 07, 2011, 09:40:06 AM

$ gpg --print-md sha256 < /dev/stdin

which gives the same results as

$ gpg --print-md sha256

ctoon6

sr. member

Activity: 350

Merit: 251

Quote from: Departure on August 07, 2011, 10:50:45 PM

Okay so I have no problems generating a SHA256 hash, personally I would use multiple hash algo's on my passowrd pharse which included a key , then I would Vigenere Encrypt that, or Xor then MD5 hash that and then finally SHA256 the result to generate a custom SHA256 key. now my question is how do I use that generated SHA256 hash in the bitcoin client as a wallet address? I have only just started using the bitcoin client as a wallet since mybitcoin problems. Could someone explain how to use a custom generated SHA256 key as there wallet address in the bitcoin client please?

https://github.com/jackjack-jj/pywallet

Departure

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Activity: 1204

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Okay so I have no problems generating a SHA256 hash, personally I would use multiple hash algo's on my passowrd pharse which included a key , then I would Vigenere Encrypt that, or Xor then MD5 hash that and then finally SHA256 the result to generate a custom SHA256 key. now my question is how do I use that generated SHA256 hash in the bitcoin client as a wallet address? I have only just started using the bitcoin client as a wallet since mybitcoin problems. Could someone explain how to use a custom generated SHA256 key as there wallet address in the bitcoin client please?

JoelKatz

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Democracy is vulnerable to a 51% attack.

Quote from: casascius on August 07, 2011, 10:11:41 PM

While I wouldn't put it past anyone, that rainbow table is going to be ridiculously slow to build to the point of near infeasibility. The operation of deriving the public key from the private key, as I'm sure you know, is super expensive in CPU time.

You only need to do it once. But yeah, trillions is going to be awfully tough.

casascius

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The Casascius 1oz 10BTC Silver Round (w/ Gold B)

Quote from: JoelKatz on August 07, 2011, 07:52:29 PM

Quote from: casascius on August 07, 2011, 10:53:34 AM

I am not sure rainbow tables would be a concern. Rainbow tables would help someone get your passphrase from your 32-byte private key, but they don't even have that. They don't even have your public key either if you have never sent funds from the address.

That's not the way they would do the attack. They would build a rainbow table of a few trillion passphrases and the corresponding bitcoin addresses. Everytime a new bitcoin address appeared in the hash chain, they would check that address against the rainbow table. If they found a match, they would derive the private key again and claim the funds immediately.

While I wouldn't put it past anyone, that rainbow table is going to be ridiculously slow to build to the point of near infeasibility. The operation of deriving the public key from the private key, as I'm sure you know, is super expensive in CPU time.

casascius

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Activity: 1386

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The Casascius 1oz 10BTC Silver Round (w/ Gold B)

Quote from: jackjack on August 07, 2011, 07:06:13 PM

Quote from: TiagoTiago on August 07, 2011, 06:16:25 PM

Are people really gonna be imaginative enough with the phrases for the risk of collision to be negligible?

My program refuses passphrases below 40 characters or 7 words, casascius should do that too...

Yeah, mine does that too.
The rules aren't exactly the same, but close. And if you mix symbols, uppercase, and lowercase, and numbers together, it will let you do a somewhat shorter phrase.

Topic: Mental Bitcoin Wallet: I have real bitcoins stored in my head. - page 4. (Read 12759 times)