Cryptosystem

A crypto- system is generally a system that deals with cryptography. As a fixed term, the term takes on behalf of RSA cryptosystem using. The term cryptosystem, however, be understood in different contexts different things. Some authors limits the term of the cryptosystem on an encryption method. Others use it for other cryptographic systems, such as digital signatures. Because of this ambiguity is not recommended in RFC 2828 obsolete by the use of this term:

In the current RFC 4949, which replaced RC 2828, shall not be more discouraged.