Quote from: DBordello on January 13, 2014, 06:37:26 PM

This is a dangerous way to do things. There isn't really a "sender address". There are just previous outputs that are used as inputs.

Additionally, people using online wallets, such as Mt.Gox, do not necessarily get credited for transactions that go back to the "sender address".

but for betting or dice game is perfect.

and for service i think is possible use signed message.

even with the difficulty of the case and imperfections, I want to create services without user db.
I want to create services where you just have a wallet