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Identity / Authentication

Verifies identity, determines permissions, and logs activity for users → AAA

MFA

Requires multiple independent credentials (ex: password + phone)

SSO

Allows one login to access multiple systems

LDAP

Directory protocol used to query and manage users/devices

SAML

Exchanges authentication data (often for SSO) using XML

OAuth

Delegates access without sharing credentials (used in APIs)

OIDC

Adds authentication layer on top of OAuth

PAP

Sends passwords in plain text for authentication

CHAP

Uses challenge/response to avoid sending passwords directly

RADIUS

Centralized authentication system used in networking devices

TACACS+

More secure centralized authentication with full packet encryption

HSM

Hardware-based secure key storage and cryptographic operations

OTP

Generates a temporary, one-time login code

FIDO

Passwordless authentication using biometrics or tokens

TCP

Ensures reliable, ordered data transmission between hosts

UDP

Sends fast, connectionless data without guarantees

IP

Provides logical addressing and routing of packets

NAT

Translates private IPs to public IPs for internet access

PAT

Uses port numbers to map multiple devices to one IP

DNS

Resolves domain names to IP addresses

DHCP

Automatically assigns IP configuration to devices

ARP

Maps IP addresses to MAC addresses on a LAN

ICMP

Sends error messages and diagnostic info (ex: ping)

SNMP

Collects and manages network device information

SMB

File and printer sharing protocol (Windows)

FTP

Transfers files between systems (unencrypted)

SFTP

Secure file transfer over SSH

TFTP

Simple file transfer with no authentication

HTTP

Transfers web data between client and server

HTTPS

Encrypts web traffic using TLS

NTP

Synchronizes system time across networks

SSL

Legacy encryption protocol for securing communications

TLS

Modern encryption protocol replacing SSL

IPsec

Secures IP communications using encryption/authentication

ESP

Encrypts payload data in IPsec tunnels

AH

Provides integrity/authentication for IP packets

SSH

Secure remote command-line access

AES

Symmetric encryption standard widely used today

DES

Older symmetric encryption standard (insecure)

3DES

Applies DES encryption three times for more security

RSA

Asymmetric encryption used for key exchange/digital signatures

ECC

Efficient asymmetric encryption using elliptic curves

PKI

Framework for managing digital certificates and keys

CA

Issues and verifies digital certificates

CRL

List of revoked/invalid certificates

OCSP

Real-time certificate validation service

PFS

Ensures session keys are not compromised if long-term key is exposed

DoS

Overwhelms a system with traffic from one source

DDoS

Overwhelms a system using many distributed sources

MITM

Intercepts and potentially alters communication between parties

XSS

Injects malicious scripts into web pages

SQLi

Injects malicious SQL queries into a database

CSRF

Tricks a user into performing unintended actions on a site

RCE

Executes malicious code remotely on a system

APT

Long-term, targeted attack by a skilled adversary

RAT

Malware that provides remote control of a system

BOT

Network of infected devices controlled remotely

C2

Server used by attackers to control compromised systems

Vishing

Phishing attack using phone calls

Smishing

Phishing attack using text messages

IDS

Monitors network traffic and alerts on suspicious activity

IPS

Actively blocks malicious traffic in real time

SIEM

Aggregates and analyzes logs for threat detection

SOAR

Automates incident response and security workflows

EDR

Detects and responds to threats on endpoints

XDR

Correlates threats across endpoints, network, and cloud

DLP

Prevents sensitive data from leaving the organization

CASB

Controls access to cloud services and enforces policies

NGFW

Firewall with advanced inspection (application awareness)

WAF

Filters and protects web applications from attacks

NAC

Controls device access to the network based on policy

IaaS

Provides virtualized computing infrastructure

PaaS

Provides platform for app development without managing hardware

SaaS

Provides software accessible over the internet

VPC

Isolated virtual network within a cloud environment

VPN

Secure tunnel for remote network access

SDN

Centralized network control using software

SASE

Combines networking and security into a cloud-delivered service

ZTNA

Enforces strict identity-based access (no implicit trust)

CIA

Core principles of securing data (protect, ensure accuracy, ensure access)

GRC

Framework for managing risk and compliance

GDPR

EU regulation for data protection/privacy

HIPAA

US law protecting healthcare data

PCI DSS

Standard for securing payment card data

SOX

US law for financial reporting integrity

AUP

Defines acceptable user behavior on systems

SLA

Defines expected service performance levels

MOU

Agreement outlining mutual responsibilities

NDA

Protects confidential information legally

BIA

Identifies impact of business disruptions

DRP

Plan to restore IT systems after disaster

BCP

Plan to maintain operations during disruption

PUP

Potentially unwanted software bundled with installs

DLL

Shared library used by programs in Windows

EXE

Executable program file

MSI

Installer package for Windows software