Can I take a cheat sheet into the Security+ exam?

No. Security+ is a proctored exam and no notes are allowed. Use this as a final-revision summary before exam day, not during it.

Security+ SY0-701 Cheat Sheet: Acronyms, Ports & Concepts

A quick-revision summary for CompTIA Security+ (SY0-701). Use it in the final days before the exam to check recall. It is a study aid only — you cannot bring notes into the proctored exam.

Security control categories and types

Categories	Types
Technical, Managerial, Operational, Physical	Preventive, Deterrent, Detective, Corrective, Compensating, Directive

Expect questions that ask for both at once (for example, a security guard is a physical, deterrent control).

Common ports to know

Port	Service
22	SSH / SFTP
23	Telnet (insecure)
25	SMTP
53	DNS
80	HTTP
443	HTTPS / TLS
389 / 636	LDAP / LDAPS
3389	RDP
161 / 162	SNMP
445	SMB

Pattern: the secure version usually swaps a plaintext protocol for a TLS-protected one (HTTP→HTTPS, LDAP→LDAPS).

Cryptography at a glance

Concept	Key idea
Symmetric	One shared key; fast; used for bulk data (AES)
Asymmetric	Public/private key pair; key exchange and signatures (RSA, ECC)
Hashing	One-way; integrity and password storage (SHA-2); add a salt
Digital signature	Hash encrypted with the sender’s private key; proves integrity and origin
PKI	Certificates + CAs bind identities to public keys

Attacks → mitigations

Attack	Typical mitigation
Phishing / social engineering	Awareness training, email filtering, MFA
Malware / ransomware	EDR, patching, least privilege, offline backups
On-path (man-in-the-middle)	TLS, certificate validation
SQL injection	Input validation, parameterised queries
DDoS	Rate limiting, CDN/scrubbing, redundancy
Password attacks	MFA, lockout policies, salted hashing

Must-know acronyms

Acronym	Meaning
CIA	Confidentiality, Integrity, Availability
AAA	Authentication, Authorization, Accounting
MFA / SSO	Multi-Factor Authentication / Single Sign-On
SIEM / SOAR	Security Information and Event Management / Orchestration, Automation and Response
IDS / IPS	Intrusion Detection / Prevention System
DLP / EDR	Data Loss Prevention / Endpoint Detection and Response
PKI / CA	Public Key Infrastructure / Certificate Authority
CRL / OCSP	Certificate Revocation List / Online Certificate Status Protocol
RTO / RPO	Recovery Time Objective / Recovery Point Objective
MTTR / MTBF	Mean Time To Repair / Mean Time Between Failures

CompTIA Security+ (SY0-701) Cheat Sheet