Commonly Used Cybersecurity Acronyms

Acronyms are everywhere in cybersecurity, and understanding them is vital to navigate technical documentation, compliance requirements, and industry conversations. We've consolidated a list of commonly used acronyms from our internal guides, NIST publications, and email communications to help you stay informed.

In today's digital landscape, understanding cybersecurity terminology isn't just for IT specialists. Small and midsize businesses face the same threats as larger companies but often with fewer resources to combat them. This guide breaks down the most important cybersecurity acronyms you'll encounter, helping you communicate more effectively with security professionals and make informed decisions about protecting your digital assets.

Cybersecurity Acronym Glossary

Below is a curated list of acronyms and their definitions. This glossary is sourced from documents such as the Assessment Guide, NIST IR publications, and insider threat manuals, as well as email exchanges with our team.

2FA/MFA

Two-Factor Authentication/Multi-Factor Authentication - Security processes requiring users to verify identity through multiple methods beyond just a password.

5G

Fifth Generation Wireless - Modern cellular network standard.

AAA

Authentication, Authorization, Accounting - Framework for controlling access and logging usage.

ACL

Access Control List - Rules that decide what traffic is allowed or denied.

AES

Advanced Encryption Standard - A specification for the encryption of electronic data.

AP

Access Point - Device that connects wireless clients to a wired network.

API

Application Programming Interface - A set of rules that allows programs to talk to each other.

APT

Advanced Persistent Threat - Sophisticated, targeted cyber attacks where unauthorized users gain and maintain long-term access.

ARP

Address Resolution Protocol - Maps IP addresses to MAC addresses.

AS

Autonomous System - A collection of IP networks under one administrative domain, identified by an ASN.

ATM

Asynchronous Transfer Mode - Old but once-popular cell-based switching tech.

BER

Bit Error Rate - Number of bit errors in transmission.

BGP

Border Gateway Protocol - The "postal service" of the internet, used between ISPs.

BPDU

Bridge Protocol Data Unit - Control message used in STP.

BSSID

Basic Service Set Identifier - MAC address of an access point.

BW

Bandwidth - Maximum rate of data transfer.

BYOD

Bring Your Own Device - Policy allowing personal devices on corporate networks.

CA

Certificate Authority - Trusted entity that issues digital certificates.

CASB

Cloud Access Security Broker - Software that sits between cloud service users and cloud applications.

CDN

Content Delivery Network - A distributed platform of servers that helps minimize delays in loading web page content.

CDP

Cisco Discovery Protocol - Cisco proprietary device discovery protocol.

CIRP

Cyber Incident Response Plan - A documented approach to addressing and managing cybersecurity incidents.

CISO

Chief Information Security Officer - Executive responsible for an entity's information and data security.

CMMC

Cybersecurity Maturity Model Certification - A unified standard for implementing cybersecurity across the defense industrial base.

CoS

Class of Service - Layer 2 traffic prioritization marking.

CRM

Customer Relationship Management - Systems used to manage customer data and interactions.

CSIRT

Computer Security Incident Response Team - A group responsible for receiving, reviewing, and responding to computer security incident reports.

CSRM

Cybersecurity Risk Management - The process of identifying, analyzing, evaluating, and addressing cybersecurity risks.

CVSS

Common Vulnerability Scoring System - A framework for rating the severity of computer system security vulnerabilities.

DDoS

Distributed Denial of Service - Attack that floods systems with traffic to disrupt service.

DFARS

Defense Federal Acquisition Regulation Supplement - A set of cybersecurity regulations for defense contractors.

DFS

Dynamic Frequency Selection - Automatically avoids radar frequencies in Wi-Fi.

DHCP

Dynamic Host Configuration Protocol - Hands out IP addresses automatically.

DKIM

DomainKeys Identified Mail - An email authentication method designed to detect email spoofing.

DLP

Data Loss Prevention - Tools that prevent unauthorized exfiltration of sensitive data.

DMARC

Domain-based Message Authentication, Reporting, and Conformance - An email authentication protocol.

DMZ

Demilitarized Zone - A network segment between the internet and LAN for public-facing servers.

DNS

Domain Name System - Translates human-friendly names into IP addresses.

DoS

Denial of Service - Attack that disrupts availability by flooding resources.

DSCP

Differentiated Services Code Point - Field in IP header for QoS marking.

DSL

Digital Subscriber Line - Broadband over telephone lines.

EAP

Extensible Authentication Protocol - Framework for authentication over Wi-Fi and PPP.

ECMP

Equal-Cost Multi-Path - Load balancing traffic across multiple equal-cost routes.

EDR

Endpoint Detection and Response - Tools that continuously monitor endpoints to detect and respond to cyber threats.

EGP

Exterior Gateway Protocol - General term for routing protocols used between ASes.

EIGRP

Enhanced Interior Gateway Routing Protocol - Cisco proprietary hybrid routing protocol.

EVPN

Ethernet VPN - MPLS/BGP-based Layer 2 VPN solution.

FHRP

First Hop Redundancy Protocol - Family of protocols providing default gateway redundancy.

FMEA

Failure Mode Effects Analysis - A step-by-step approach for identifying potential failures.

FQDN

Fully Qualified Domain Name - Complete domain name (e.g., host.example.com).

FTP

File Transfer Protocol - Protocol for file transfers.

GDPR

General Data Protection Regulation - European Union regulation on data protection and privacy.

GRE

Generic Routing Encapsulation - Encapsulates packets to create point-to-point tunnels.

HIPAA

Health Insurance Portability and Accountability Act - U.S. legislation for safeguarding medical information.

HMAC

Hash-Based Message Authentication Code - Method for verifying message integrity/authenticity.

HSRP

Hot Standby Router Protocol - Cisco protocol for gateway redundancy.

HTTP

HyperText Transfer Protocol - Foundation of web communication.

HTTPS

HyperText Transfer Protocol Secure - Encrypted HTTP using TLS.

IaaS

Infrastructure as a Service - Cloud model providing compute/storage/network.

IAM

Identity and Access Management - Framework of policies ensuring appropriate access to resources.

ICMP

Internet Control Message Protocol - Used for network diagnostics (ping, traceroute).

IDS

Intrusion Detection System - Detects malicious activity but doesn't block.

IGMP

Internet Group Management Protocol - Manages multicast group memberships.

IGP

Interior Gateway Protocol - General term for routing protocols used within an AS.

IKE

Internet Key Exchange - Protocol used in IPsec for secure key negotiation.

IMAP

Internet Message Access Protocol - Retrieves and manages email.

IoT

Internet of Things - Network of physical objects embedded with sensors and software.

IP

Internet Protocol - Provides addressing and routing of packets.

IPS

Intrusion Prevention System - Detects and blocks malicious network traffic.

IPsec

Internet Protocol Security - Encryption/authentication protocol suite for IP traffic.

IS-IS

Intermediate System to Intermediate System - Link-state routing protocol similar to OSPF.

ISDN

Integrated Services Digital Network - Circuit-switched digital transmission standard (legacy).

ISP

Internet Service Provider - Company that provides internet access.

Jitter

Variation in packet delay times.

Kerberos

Authentication protocol using tickets and symmetric cryptography.

KPI

Key Performance Indicator - Measurable values demonstrating how effectively objectives are achieved.

L2TP

Layer 2 Tunneling Protocol - VPN tunneling protocol, often paired with IPsec.

LACP

Link Aggregation Control Protocol - Bundles multiple network links for redundancy/bandwidth.

LAN

Local Area Network - A small local network (like in your house or office).

LDAP

Lightweight Directory Access Protocol - Protocol for accessing directory services.

LLDP

Link Layer Discovery Protocol - Vendor-neutral device discovery protocol.

LTE

Long-Term Evolution - Standard for 4G wireless broadband.

MAC

Media Access Control - Unique hardware address of a network interface card.

MACsec

Media Access Control Security - Provides encryption and integrity for traffic on Ethernet links.

MAN

Metropolitan Area Network - Regional-scale network between LANs and WANs.

MDM

Mobile Device Management - Software allowing IT administrators to control and secure devices.

MPLS

Multiprotocol Label Switching - High-performance routing method using labels instead of IP lookups.

MSS

Maximum Segment Size - Largest segment of TCP data a device is willing to receive.

MSSP

Managed Security Service Provider - Companies offering outsourced monitoring and management of security systems.

MTU

Maximum Transmission Unit - The largest packet size a network link can handle.

MU-MIMO

Multi-User, Multiple Input, Multiple Output - Wi-Fi tech allowing simultaneous data streams.

NAT

Network Address Translation - Maps private IPs to a public IP.

NFV

Network Functions Virtualization - Virtualizing network services (firewalls, routers).

NIST

National Institute of Standards and Technology - Agency developing cybersecurity standards.

NSX

Network Virtualization and Security Platform - VMware's SDN product.

NTP

Network Time Protocol - Synchronizes clocks over a network.

OFDM

Orthogonal Frequency Division Multiplexing - Modulation technique used in Wi-Fi and LTE.

OpRisk

Operational Risk - Risk of loss from inadequate or failed internal processes.

OSPF

Open Shortest Path First - A routing protocol for finding efficient paths inside a network.

OTP

One-Time Password - Password valid for only one login session.

OWASP

Open Web Application Security Project - Online community producing web application security resources.

PaaS

Platform as a Service - Cloud model providing platforms for applications.

PAT

Port Address Translation - A type of NAT that also maps ports.

PCI DSS

Payment Card Industry Data Security Standard - Information security standard for handling credit card data.

PHI

Protected Health Information - Individually identifiable health information protected under HIPAA.

PII

Personally Identifiable Information - Data that could potentially identify a specific individual.

PKI

Public Key Infrastructure - Framework for managing certificates and keys.

PoE

Power over Ethernet - Supplies electrical power to devices over the network cable.

POP3

Post Office Protocol version 3 - Downloads email from a server.

PPP

Point-to-Point Protocol - Protocol for direct connections between two nodes.

PPPoE

Point-to-Point Protocol over Ethernet - Used by ISPs to authenticate broadband subscribers.

Q-in-Q

Technique for stacking VLAN tags in Ethernet frames.

QBR

Quarterly Business Review - Regular assessment of business performance.

QoS

Quality of Service - Prioritization of network traffic for performance.

RADIUS

Remote Authentication Dial-In User Service - Authentication/authorization/accounting protocol.

RARP

Reverse Address Resolution Protocol - Maps MAC addresses back to IPs (obsolete).

RBAC

Role-Based Access Control - Method of restricting system access based on roles.

RDP

Remote Desktop Protocol - Microsoft protocol for remote GUI sessions.

RIP

Routing Information Protocol - Early distance-vector routing protocol.

RMF

Risk Management Framework - A structured approach to identify, assess, and manage risk.

RMM

Remote Monitoring and Management - Software used by MSPs to monitor client endpoints.

RSSI

Received Signal Strength Indicator - Measurement of Wi-Fi signal power.

RST

Reset Flag - TCP flag that immediately terminates a connection.

RSTP

Rapid Spanning Tree Protocol - Faster-converging STP variant.

RTT

Round-Trip Time - Time it takes for a packet to go to a destination and back.

SaaS

Software as a Service - Software licensing and delivery model.

SCP

Secure Copy Protocol - File transfer over SSH.

SDH

Synchronous Digital Hierarchy - SONET equivalent used outside North America.

SDN

Software Defined Networking - Abstracts control of the network into software.

SFTP

SSH File Transfer Protocol - Secure file transfer over SSH.

SIEM

Security Information and Event Management - Software providing real-time analysis of security alerts.

SMTP

Simple Mail Transfer Protocol - Protocol for sending email.

SNMP

Simple Network Management Protocol - Manages and monitors network devices.

SNR

Signal-to-Noise Ratio - Signal strength compared to background noise.

SOC

Security Operations Center - Facility where security professionals monitor and protect against threats.

SONET

Synchronous Optical Network - Standard for fiber optic transport (North America).

SPF

Sender Policy Framework - Email authentication method to detect forging sender addresses.

SQL

Structured Query Language - Programming language used to communicate with databases.

SSH

Secure Shell - Encrypted remote management protocol.

SSID

Service Set Identifier - The name of a Wi-Fi network.

SSL

Secure Sockets Layer - Old standard for encryption, now replaced by TLS.

SSO

Single Sign-On - Authentication process allowing access to multiple applications with one login.

STP

Spanning Tree Protocol - Prevents loops in switch networks.

Syslog

Standard for logging system messages across a network.

TACACS

Terminal Access Controller Access-Control System - Original AAA protocol.

TACACS+

Terminal Access Controller Access-Control System Plus - Cisco protocol for AAA.

TCP

Transmission Control Protocol - Reliable, connection-oriented transport layer protocol.

TFTP

Trivial File Transfer Protocol - Lightweight, insecure file transfer protocol.

Throughput

Actual rate of successful data delivery.

TLS

Transport Layer Security - Modern encryption standard used in HTTPS, VPNs, etc.

UDP

User Datagram Protocol - Lightweight, connectionless transport layer protocol.

VLAN

Virtual Local Area Network - Logical separation of networks on the same switch.

VNF

Virtual Network Function - Virtualized instance of a network appliance.

VoIP

Voice over Internet Protocol - Phone calls over IP networks.

VPN

Virtual Private Network - Encrypted tunnel between networks or devices.

VRRP

Virtual Router Redundancy Protocol - Vendor-neutral gateway redundancy protocol.

VTP

VLAN Trunking Protocol - Cisco protocol for distributing VLAN info.

VXLAN

Virtual Extensible LAN - Encapsulation protocol for creating overlay networks in data centers.

WAF

Web Application Firewall - A firewall that filters and blocks HTTP/S traffic.

WAN

Wide Area Network - A network that spans a large geographic area.

WEP

Wired Equivalent Privacy - Old, insecure Wi-Fi encryption.

WPA2

Wi-Fi Protected Access 2 - Common Wi-Fi encryption standard.

WPA3

Wi-Fi Protected Access 3 - Current Wi-Fi security protocol.

XDR

Extended Detection and Response - Security approach unifying multiple security products.

Zero-day

Security flaw unknown to the software vendor that hackers can exploit before it's patched.

ZTA

Zero Trust Architecture - Security model requiring strict identity verification for everyone.

Why Understanding These Acronyms Matters

For small and midsize businesses, cybersecurity knowledge translates directly to risk management. When you understand these terms, you can:

• Communicate effectively with IT security professionals
• Make more informed decisions about security investments
• Better understand compliance requirements affecting your industry
• Assess potential vulnerabilities in your current setup
• Develop more comprehensive security policies

How to Use This Glossary

Bookmark this page or integrate these acronyms into your internal documentation. Understanding these terms can improve communication across teams and help with onboarding new staff or clients.

Consider creating flashcards from these acronyms for team training sessions, or include them in your security awareness program. Regular exposure to these terms will help staff become more comfortable with cybersecurity concepts.

Taking Action: Next Steps for Your Business

Knowledge of terminology is just the beginning. Here are practical steps to improve your cybersecurity posture:

• Conduct a security assessment using these terms as a framework
• Identify which security measures are most critical for your specific operations
• Consider working with an MSSP if in-house expertise is limited
• Implement at least basic protections like MFA and endpoint security
• Develop an incident response plan before you need it

Real-World Impact

Our clients often reference this glossary during audits, tabletop exercises, and policy development. Having a shared understanding of terminology helps reduce confusion and ensures alignment across departments.

As cyber threats continue evolving, staying informed about cybersecurity terminology helps your business maintain resilience against increasingly sophisticated attacks. While large corporations may have extensive security teams, small and midsize companies can achieve comparable protection by understanding and implementing these fundamental concepts.

Need Help with Cybersecurity Documentation?

Contact STACK Cybersecurity for assistance in building glossaries, policy templates, and training materials tailored to your business. We specialize in making complex cybersecurity concepts accessible and actionable.

Website: stackcyber.com
Email: digital@stackcyber.com
Phone: (734) 744-5300