Quote from: Etlase2 on April 29, 2013, 01:59:36 AM

Quote from: Come-from-Beyond on April 28, 2013, 02:40:19 PM

Quote from: dolfcao on April 28, 2013, 01:38:35 PM

uh, u mean one user can at most send 1440 transactions under ur condition?

Yes. It's the same as http://en.wikipedia.org/wiki/Hashcash.

The problem with using a hashcash style spam-prevention is that it almost has the opposite effect on a distributed network. One user who can make 1,440 transactions per day can have the networks bandwidth multiplied by 1,440 txes X the number of network peers. "It shows work! I must pass it on to everyone I know!" Multiply this by a botnet and you have complete network collapse. In addition, providing a nonce as proof of work with each transaction will increase the size of each transaction by at least 32 bytes, perhaps 64 bytes or more. That is a significant increase in bandwidth to avoid paying transaction fees. Proof of work as tx fees is more easily DDoS'd and less scalable.

your analysis is really valuable, the transaction fees will be 1/10000 in a fixed ratio after 100 transactions per user per day, do you think this is acceptable?