The authors discuss how encryption can be used instead of charging fees
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Transaction fees for micropayments threaten the booming online and mobile economy. Changing how the e-commerce industry imposes online transaction fees can provide a quick fix to the micropayment problem—which occurs when processing fees on such widely purchased small items as iTunes and parking exceed the merchant's margins. However, that simple business approach will provide only a stopgap measure at best because it fails to address the fact that each transaction carries fixed costs.
Implementing applied-cryptography approaches is decidedly more difficult, but it provides a far superior long-term solution. The approaches range from aggregating payments and using tamper-resistant devices to delegating policy decisions and letting users generate payment tokens...
