说明：  王小云教授虽然已经破解了sha1，但是sha1并不是由此就垮掉了，而是向着更多元、复杂的方向去发展，本文主要介绍了sha1在电子交易中的使用。
(Bruce Schneier sha1 have cracked, but not from this sha1 collapse, but toward more yuan, complicated move in the direction of development, this paper introduces the sha1 in electronic transactions use.)