Bitcoin Forum

Couldn't find any info on a Decentralized Exchange.

Is it doable? Fiat to Bitcoin?

Pre-paid cards, some kind of QR system, etc?

Just thinking out loud.

https://en.bitcoin.it/wiki/Ripple_currency_exchange

Here's my take on the decentralized exchange: https://bitcointalk.org/index.php?topic=121091.0

I think it's possible the way I presented it, but I'd like to have others with more experience give an opinion on that one way or another.

Dark Exchange: a 100% decentralized p2p exchange
I don't think it's still in development, and it probably doesn't have any nodes left either.

https://bitcointalk.org/index.php?topic=27055.msg340603#msg340603

I just installed it and connected to two peers tho there no buy orders for BTC/GBP.

Dark Exchange is an awesome idea.

Don't think it is still being developed or am I wrong?

I don't think that ripple will work without massive subsidies to convince people to be early adopters. It is nearly useless without a big network. Much more so than bitcoin.

You can however make a decentralized exchange very easily with private notes. The concept is colored coins.

Some trusted name like bitinstant colors a bunch of satoshis and promises to redeem them for 1 USD worth of btc in the future. Perhaps they can sell them for 1.005 USD in order to earn a profit.
They can publically escrow btc to demonstrate their reserve to the public. They can also earn profits by using a fractional reserve and investing the rest of the money (this would be very unstable though).

The bitinstantUSD circulate just like bitcoin, but maintain parity with the USD. They can be used for payment, hedging, or speculation about the exchange rate.

Use of these notes should be a much cheaper way of hedging against exchange rate risk then converting currency directly to USD.

yes it is possible... i have make this possible.. its sounds unbelieveable... but the biggest problem was for me to create a option to can see the balance from multisigaddresses without have all private keys... With many patience i have create a option to can trade between coins without have the fear that anybody can steal your money or can try to cheat....?

How its possible?

My decentralized exchange works because the nodeserver(Everybody the uses my Decentralized Exchange is automatically a node server) , you and your partner must sign the transaction with the private key... To make this process easily i have created and added many rpc commands with my algorithms and features to can easily build a exchange with java c++ etc... for any coin the have the same address version as bitcoin...

I have added many encryption algorithms settings to make impossible that anybody can sniff the packets... and still if anybody sniff the packets is useless then all priv keys owned youself...

the onlys decentralized coins are my bitcoin wallet and bitcrystal...

here but this projects takes many months and years ... its was very difficult and i always if anybody helpes me to supported my project...

https://bitcointalk.org/index.php?topic=966861.540

http://bitcrystal.net/

but its very difficult to add any coins to my exchange because you must have the knowledge and you must make a lot of changes in the source code of the coin... its takes many time

This technology exists. None of them use QR systems as far as I know. Search on the projects board, there are probably some related projects there.