Quote from: Stephen Gornick on November 19, 2012, 11:14:28 AM

Quote from: EskimoBob on November 18, 2012, 12:14:33 PM

Can you describe something simple and reliable that exchanges and CF sites can implement and actually use?

Kind of related is the payment protocol being discussed for Bitcoin:

Quote from: Gavin Andresen on September 10, 2012, 12:22:11 AM

We need a payment protocol with non-repudiation built in.

See https://gist.github.com/2217885 for a multisig version (the singlesig version is simpler, but the merchant <-> customer communication will be the same).

Thank you for the tip. Multisign is a nice feature if more than one person must be in charge of the coin. I have waited for this feature close to a year now.

I am not sure, how can this help a contributor (C) to prove and receiver (P) to confirm, that the coin sent to project account, via third party (CFS), are actually from contributor. I need to read up on that a bit more.

Lets say someone with mental issues (criminal/scammer) wants to scam the shares from "P".
If "P" account address was public, he-she can find out the tx numbers and go from there.
Sure, I can ask him to prove it by moving coins but this will get tedious really fast.

What if CFS adds a random confirmation code to this picture?

1) Lets say "C" sends coin to CFS, gets a confirmation code generated by CFS and a md5 hash generated from code+tx ID.
2) "P" receives the md5 hash from CFS at the same time but has no confirmation number (this is good).
3) "C" can prove the transaction with that number because code+tx_id = correct md5 hash
4) "P" also had the tx ID from the time when "C"'s coin was moved to "intermediate" address Z.

Will this do the trick?