Cheat sheets
Dense quick-reference pages for the things you look up constantly.
Common ports & protocols
The port numbers worth memorising, with transport protocol and a note on whether traffic is encrypted.
Linux command reference
The commands you reach for constantly in CTFs and on the job: enumeration, permissions, networking and searching.
HTTP status codes & security headers
Status codes grouped by class, the security-relevant ones, and the response headers that harden a site.
Cryptography quick reference
Algorithms at a glance: what to use, what's broken, and which property each primitive provides.
Networking quick reference
The OSI and TCP/IP models, protocol ports, TCP flags, common LAN attacks and a CIDR subnet table you can read at a glance.
Web attack quick reference
The OWASP Top 10:2025, cookie security flags, injection syntax to recognise and the three XSS types with a fix for each.
Windows & Active Directory quick reference
Security event IDs to know, the common credential attacks against a domain and the commands you reach for when investigating.
Governance, risk and compliance quick reference
The NIST CSF 2.0 functions, the incident response lifecycle, UK GDPR Article 5 principles and the Computer Misuse Act offences.