Articles & Guides
Useful resources for web developers and system administrators
Found 56 · Security · Reset
Security
JWT token explained: structure, decoding, and verification
JWT token explained: header.payload.signature structure, how to decode a JWT locally or online, why decoding is not verification, classic mistakes and attacks.
Security
Advertising Disclosure on Your Website: What Counts as an Ad, Where the erid Token Comes From, and How It Breaks Technically
What counts as advertising on a website, who is responsible for the label, where the erid token goes, and which technical mistakes leave a live page unlabelled.
Security
SSH Key Authentication: Generate, Install and Disable Password Login
How to generate an ed25519 SSH key, install it on a server, fix 700/600 permissions, disable password login and debug Permission denied (publickey) errors.
Security
Hosting a website for Russian users: data localisation and provider requirements
Why a Russian audience forces data residency: which sites must host locally, how the provider registry works, and how it compares with GDPR transfers.
Security
fail2ban Setup Guide: Jails, SSH Brute-Force Protection and Troubleshooting
How to install and configure fail2ban on Debian and Ubuntu: jail.local, bantime and maxretry, sshd and nginx jails, custom filters, unbanning and pitfalls.
Security
Website and IP Blacklist Check: Find Every List and Get Delisted
Website or IP blacklisted? Check Safe Browsing, SmartScreen, email DNSBLs and AbuseIPDB: dig commands, 127.0.0.x return codes and the delisting order.
Security
Website Privacy Policy: What It Must Contain and How to Publish It
Website privacy policy: who needs one, which sections it must contain, how to publish it, how to run a compliant cookie consent banner under GDPR and ePrivacy, and what fines you risk without one.
Security
Website Security Check: The Complete Checklist
Website security check: the complete checklist. How to test any website online in 5 minutes — HTTPS, security headers, CSP, cookies, malware — plus a full owner's checklist with curl examples and a layer-by-layer summary table.
Security
Website Hacked: What to Do in the First Hour
Website hacked — what to do in the first hour: a minute-by-minute plan. Isolate the site, rotate all credentials, preserve logs, find the web shell and entry point, restore from a clean backup, and close the vulnerability. With commands, a 10-step checklist, and FAQ.
Security
How to Check a Website for 152-FZ Compliance: An Owner's Checklist
A self-check checklist for a website's 152-FZ compliance: policy, voluntary consent, cookie notice, data storage in Russia, Roskomnadzor notice, HTTPS.