Identity and access
AAA separates authentication, authorization, and accounting. IAM coordinates identity and access management. MFA combines distinct authentication factors. SSO reduces repeated sign-ins, while federation extends trust across identity domains. PAM controls privileged access.
- IdP — identity provider
- SAML — Security Assertion Markup Language
- OAuth — delegated authorization framework
- OIDC — OpenID Connect authentication layer
- TOTP — time-based one-time password
- FIDO — phishing-resistant authentication standards ecosystem
Network and secure communications
TLS protects data in transit at the application/session boundary. IPsec protects IP traffic. VPN describes a protected tunnel rather than one specific protocol. DNSSEC authenticates DNS data; it does not encrypt ordinary DNS queries.
- ACL — access control list
- NAC — network access control
- WAF — web application firewall
- IDS/IPS — intrusion detection/prevention system
- ZTNA — zero trust network access
- SASE — secure access service edge
- SD-WAN — software-defined wide area network
Threat detection and operations
SIEM centralizes and analyzes security events. SOAR coordinates automated workflows. EDR focuses on endpoints, while XDR correlates signals across multiple control layers. DLP seeks to detect or prevent inappropriate data movement.
- IOC — indicator of compromise
- TTP — tactics, techniques, and procedures
- C2 — command and control
- UEBA — user and entity behavior analytics
- FIM — file integrity monitoring
- CVE — Common Vulnerabilities and Exposures
- CVSS — Common Vulnerability Scoring System
Risk, continuity, and recovery
RTO is the target time to restore a service. RPO is the acceptable data-loss window measured in time. MTD is the maximum tolerable downtime. BIA identifies operational impacts and priorities.
- BCP — business continuity plan
- DRP — disaster recovery plan
- SLE — single loss expectancy
- ARO — annualized rate of occurrence
- ALE — annualized loss expectancy
- MTTR — mean time to repair or recover
- MTBF — mean time between failures
Cryptography and trust
PKI manages certificates and trust relationships. A CA issues or signs certificates, a CSR requests one, and OCSP can provide revocation status. HSMs protect cryptographic keys and operations.
- AES — Advanced Encryption Standard
- RSA — Rivest–Shamir–Adleman public-key algorithm
- ECC — elliptic-curve cryptography
- SHA — Secure Hash Algorithm family
- HMAC — hash-based message authentication code
- TPM — trusted platform module
- PFS — perfect forward secrecy
How to study acronyms efficiently
Create two-way cards: expand the acronym, then explain its purpose and a scenario signal. Group confusing terms and state the boundary between them—for example, RTO versus RPO, IDS versus IPS, or SAML versus OAuth.
- Use recall before rereading.
- Attach each term to an asset, risk, or workflow.
- Practice choosing between neighboring concepts.
- Verify the current objectives and terminology with CompTIA.
Verify current exam details at the Official CompTIA Security+ certification page. PrepVanta is independent and is not affiliated with or endorsed by the certification provider.