Security knowledge base
Learn Website Security and Monitoring
Use these answer-first guides to understand public attack surfaces, network protocols, DNS, TLS, and the monitoring evidence that helps teams act.
External Attack Surface Management: A Practical Guide
Learn what EASM is, how external assets are discovered, how exposure changes, and how continuous monitoring supports an accurate internet-facing inventory.
Internet Networking for Security and Monitoring
TCP ports, DNS, TLS, HTTP, and service-failure guides.
DNS Security and Monitoring Guide
Learn DNS records, monitoring, DNSSEC, email authentication, TTL behavior, and how DNS changes affect security and availability.
TLS and SSL Certificate Security Guide
Learn TLS handshakes, certificate chains, hostname validation, expiration, transparency, wildcard and self-signed certificates, and HTTPS outage prevention.
Cybersecurity Glossary
Detailed protocol, attack-surface, and monitoring definitions.
Sentryx Research
Methodology and privacy-qualified internet exposure research.
External Attack Surface Monitoring
See how Sentryx turns public discovery evidence into an operational monitoring workflow.
Website Uptime Monitoring
Connect protocol knowledge to continuous endpoint checks and incident evidence.
Why Outside-In Monitoring Matters
Learn why public customer experience differs from internal health.
How to Monitor SSL Certificate Expiry
Build an operational certificate-expiry monitoring process.
DMARC, SPF, and DKIM Email Trust
Understand how public email authentication records work together.