DES algorithm: The National Bureau of Standards of the United States began to study the data encryption standards of computer systems in departments other than the Ministry of National Defense in 1973, and issued two public announcements to solicit encryption algorithms in May of 15 and August 27th of 1974. 1977 1, promulgated by the U.S. government: adopt the scheme designed by IBM as the official data encryption standard for unclassified data (DES? Data encryption standard).

RSA is the first algorithm that can be used for data encryption and digital signature. Easy to understand and operate, and very popular. The name of the algorithm is named after the inventors: Ron Livingstone, adi shamir and Leonard Aderman. However, the security of RSA has not been proved theoretically. It has experienced various attacks and has not been completely breached so far.