英语翻译Since e-money is just a bunch of bits,a piece of e-money

英语翻译
Since e-money is just a bunch of bits,a piece of e-money is very easy to duplicate.Since the copy is indistinguishable from the original you might think that counterfeiting would be impossible to detect.A trivial e-money system would allow me to copy of a piece of e-money and spend both copies.I could become a millionaire in a matter of a few minutes.Obviously,real e-money systems must be able to prevent or detect double spending.
Online e-money systems prevent double spending by requiring merchants to contact the bank's computer with every sale.The bank computer maintains a database of all the spent pieces of e-money and can easily indicate to the merchant if a given piece of e-money is still spendable.If the bank computer says the e-money has already been spent,the merchant refuses the sale.This is very similar to the way merchants currently verify credit cards at the point of sale.
Offline e-money systems detect double spending in a couple of different ways.One way is to create a special smart card containing a tamper-proof chip called an Observer (in some systems).Te Observer chip keeps a mini database of all the pieces of e-money spent by that smart card.If the owner of the smart card attempts to copy some e-money and spend it twice,the imbedded Observer chip would detect the attempt and would not allow the transaction.Since the Observer chip is tamper-proof,the owner cannot erase the mini-database without permanently damaging the smart card.

由于电子货币只是一堆的位,一电子一块钱是很容易复制.由于副本从原始区分你可能认为,假冒是不可能发现.微不足道的电子货币系统将允许我复制的电子货币和消费两个副本件.我可以成为一个数分钟内百万富翁.显然,真正的...