Digest::RMD160
class Digest::RMD160
Parent:Digest::Base
一个计算消息摘要的类：使用的是由Hans Dobbertin，Antoon Bosselaers和Bart Preneel设计的RIPEMD-160密码散列函数。
RMD160计算160位（20字节）的摘要。
例子
require 'digest'
# Compute a complete digest
Digest::RMD160.hexdigest 'abc' #=> "8eb208f7..."
# Compute digest by chunks
rmd160 = Digest::RMD160.new # =>#<Digest::RMD160>
rmd160.update "ab"
rmd160 << "c" # alias for #update
rmd160.hexdigest # => "8eb208f7..."
# Use the same object to compute another digest
rmd160.reset
rmd160 << "message"
rmd160.hexdigest # => "1dddbe1b..."
