many people talk about offline spend

[PRCman]

They said print the wallet on paper, then spend off line

But the person who spend the money could keep the wallet, and spend it online before the person who receive the money did that.

[1714079069]

1714079069

[1714079069]

1714079069

[kjj]

Yes.  That is the flaw in these schemes.

For offline spending, you need a trusted third party.  Which isn't that big of a deal, really.  The current financial reality is trusted third parties as far as the eye can see.

[PRCman]

Yes.  That is the flaw in these schemes.

For offline spending, you need a trusted third party.  Which isn't that big of a deal, really.  The current financial reality is trusted third parties as far as the eye can see.

Is the wallet a pgp private key? What kind of algorithms  are supported?

[kjj]

Er, wallets and addresses are kinda complicated.

If you understand public key cryptography, you can think of the wallet as holding private keys, and each of your addresses being a public key that matches one of your private keys.  The reality is a bit more involved though, or at least it can be.

[PRCman]

Er, wallets and addresses are kinda complicated.

If you understand public key cryptography, you can think of the wallet as holding private keys, and each of your addresses being a public key that matches one of your private keys.  The reality is a bit more involved though, or at least it can be.

which public key cryptography algorithm does bitcoin supports ex. RSA1024 2048; ECC 190, 239 , does that supported?

[davout]

which public key cryptography algorithm does bitcoin supports ex. RSA1024 2048; ECC 190, 239 , does that supported?

ecdsa

[db]

But the person who spend the money could keep the wallet, and spend it online before the person who receive the money did that.

If you trust them or verify and claim the note before you let them out of your sight you can use this:

http://forum.bitcoin.org/?topic=3716.0

If not and you don't think they can forge one you can use these:

http://bitbills.com/

[adrian33]

Check out https://github.com/bitcoin-labs/paper-keys

[wujh]

I guess the bitcoin will turn to be some kind of virtue  GOLD, and there will be a lot of virtue CURRENCY based on the bitcoin, like USD based on gold in 1944-1971.

There will be some guy claim that they promise to buy back the CURRENCY they issue with a decided rate, just like US Gov claimed in 1944. And if:

1) Their CURRENCY  is more convenient to use than BTC;
2)They have lots of BTC at first;

Their currency will start to be more popular than BTC, and later, they will:

3) issue more CURRENCY than the BTC hold in their hands at the decided rate.

[PRCman]

I guess the bitcoin will turn to be some kind of virtue  GOLD, and there will be a lot of virtue CURRENCY based on the bitcoin, like USD based on gold in 1944-1971.

There will be some guy claim that they promise to buy back the CURRENCY they issue with a decided rate, just like US Gov claimed in 1944. And if:

1) Their CURRENCY  is more convenient to use than BTC;
2)They have lots of BTC at first;

Their currency will start to be more popular than BTC, and later, they will:

3) issue more CURRENCY than the BTC hold in their hands at the decided rate.

but making fake currency of BTC is not a crime, It's really easy to make fake papers, right?
If someone need online spend, they won't need currency of BTC, they can use BTC directly, for ofline cases there is no way to verify the currency (fake of copied).....