| HMAC | Hash Message Authentication Code |
| MASS | Message Authentication Signature Standard |
| MIC | Message Integrity Check/Code |
| AS | Authentication Server [engl.] |
| RPA | Remote Passphrase Authentication |
| SPA | Secure Password Authentication |
| PAM | Pluggable Authentication Module |
| PAP | Password Authentication Protocol |
| EAPOL | Extensible Authentication Protocol Over LAN |
| AUC | Authentication Center [engl.] |
| EAP | Extensible Authentication Protocol |
| MDA | Mediated Digest Authentication |
| AH | Authentication Header [engl.] Authentifizierung für Daten und IP-Header |
| DAA | Digest Access Authentication |
| CHAP | Cryptographic Handshake Authentication Protocol Kryptographisches Authentifizierungsprotokoll |
| LEAP | Lightweight Extensible Authentication Protocol |
| SPAP | Shiva Password Authentication Protocol |
| JAAS | Java Authentication and Authorization Service |
| WAPI | Wireless Authentication and Privacy Infrastructure |
| SASL | Simple Authentication and Security Layer |
| DASS | Ditributed Authentication Security Service |
| UAM | User Authentication Method / Module |
| PEAP | Protected Extensible Authentication Protocol |
| AUC | Authentication/Authority Centre [engl.] |
| CRAM | Challenge Response Authentication Mechanism |
| EAPOE | Extensible Authentication Protocol Over Ethernet |
| NMAS | Novell Modular Authentication Services |
| CHAP | Challenge Handshake Authentication Protocol Authentifizierungsprotokoll |
| RADIUS | Remote Authentication Dial In User Service |
| HAAPI | Human Authentication Application Program Interface |
| RADIUS | Remote Access / Authentication Dial-In User Service |
| EOM | End Of Message |
| MSG | Program Message |
| MU | Message Unit |
| MID | Message Identifier |
| MQ | Message Queuing |
| SOM | Start Of Message |
| RFNM | Ready For Next Message |
| IPM | Interpersonal Message |
| MD5 | Message Digest 5 |
| COM | Continuation Of Message |
| CMS | Changeable Message Sign |
| MSP | Message Security Protocol |
| CMR | Corporate Message Recovery |
| MSR | Message Service Routine |
| MTA | Message Transfer Architecture [AT&T] |
| MTP | Message Transfer Part |
| DMG | Distress Message Generator |
| CMS | Cryptographic Message Syntax |
| OMM | Output Message Manual |