RC6 was a patented encryption algorithm (U.S. Patent 5,724,428 and U.S. Patent 5,835,600); however, the patents expired between 2015 and 2017.
RC6是一个专利加密算法(美国专利5,724,428，美国专利5,835,600)；但是，专利已经在2015年到2017年间过期。