| Subject | English | Spanish |
| comp., MS | Challenge Handshake Authentication Protocol A challenge-response authentication protocol for Point-to-Point Protocol (PPP) connections described in RFC 1994. It uses the industry-standard MD5 hashing algorithm to hash the combination of a challenge string issued by the authenticating server and the user's password in the response | Protocolo de autenticación por desafío mutuo (CHAP) |