Authentication Methods in Networks

Vocabulary flashcards covering key authentication methods and concepts discussed in the video lecture.

Authentication

The process of determining whether someone or something is in fact who they claim to be.

Local Authentication

User enters a username and password on a device; credentials are encrypted and stored on the device and checked locally.

LDAP (Lightweight Directory Access Protocol)

A centralized directory service for users, groups, and devices; cross‑platform; uses port 389 for plain text, with LDAPS using port 636 for SSL/TLS.

LDAPS

LDAP over SSL/TLS; uses port 636 to protect data in transit.

Active Directory (AD)

Microsoft’s LDAP-based directory service in Windows domains; organizes clients, servers, devices, users, and groups and supports security/policy features like group policies.

Kerberos

Authentication protocol in Windows domains that uses tickets and mutual authentication; avoids sending passwords over the network; relies on a Key Distribution Center (KDC) and a domain controller.

KDC (Key Distribution Center)

Component of Kerberos that authenticates clients and issues tickets (e.g., TGT) and service tickets.

Ticket Granting Ticket (TGT)

Ticket issued by the KDC after initial authentication; used to obtain service tickets for accessing resources.

Service Ticket / Session Key

Ticket issued to access a specific resource; presented to the resource; may include a session key for the interaction.

Single Sign-On (SSO)

Authentication system where one set of credentials grants access to multiple resources; reduces password management but can be risky if credentials are compromised.

SAML

XML-based data format for exchanging authentication/authorization data between an identity provider and a service provider; often used to enable SSO; commonly paired with SOAP.

Identity Provider (IdP)

Entity that authenticates the user and vouches for their identity to the service provider.

Service Provider (SP)

The resource or service that relies on the IdP’s assertion of the user’s authentication.

RADIUS (Remote Authentication Dial-In User Service)

Centralized authentication/authorization/accounting for dial-up, VPN, and wireless using 802.1X and EAP; uses port 1812 (authentication) and 1813 (accounting); cross‑platform standard.

TACACS Plus (Takis Plus in notes)

Cisco-proprietary AAA protocol (not cross‑platform); provides authentication, authorization, and accounting; runs over TCP; often used with Cisco devices.

Time-based Authentication (TOTP)

Generates a one-time password based on a shared secret and the current time; codes expire quickly (e.g., 30–60 seconds) and are used in MFA with apps like Google/Microsoft Authenticator or hardware tokens like RSA/YubiKey; resist replay attacks.