secure-os wrote
Sep 5, 2026 in linux, logging, auditd - journalctl, ausearch, aureport, last, lastb and auditctl cover almost everything you will ever need to ask a Linux system about its own past. What each one sees, what none of them see, and why a log on the machine is evidence of a different quality than a log shipped off it.
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Sep 5, 2026 in gpg, encryption, troubleshooting - The message is precise and almost everyone misreads it. GPG is not saying your key is wrong, it is saying the key that can open this file is not in the keyring it is looking at. Here is how to find out which key the file wants, and the four reasons yours is missing.
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Sep 5, 2026 in usb, boot, linux - You can tell whether a stick will boot by reading its partition table, its boot flag and its EFI directory. Three commands on Linux, two on Windows, one on macOS. What each check proves, and the one it cannot.
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Sep 5, 2026 in ssh, authentication, linux - A password is a secret you send. A key is a secret you never send. That one distinction settles most of the argument, decides what a compromised server can steal from you, and explains why key authentication is not simply a stronger password.
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Sep 5, 2026 in detection, intrusion, monitoring - A canary token is a file, a URL or a credential that has no legitimate use. Nothing should ever touch it, so the day something does, you learn about an intrusion your other tools missed. What they detect, where to place them, and the two ways people ruin them.
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Sep 4, 2026 in vpn, anonymity, threat-model - A double VPN sends your traffic through two servers instead of one. What that genuinely protects against, what it costs in speed and latency, and the common cases where it changes nothing at all because the weak link is somewhere else entirely.
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Sep 4, 2026 in surveillance, privacy, travel - A hidden camera is found by systematic inspection, not by a gadget. Which objects actually host them, why the lens reflection trick works and when it does not, what a network scan can and cannot tell you, and what to do if you find one.
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Sep 4, 2026 in vpn, privacy, isp - Your provider stops seeing which sites you visit the moment a VPN is on. It still sees that you are using one, how much you send and when. And browsing history is a separate thing entirely, because it lives on your device, not at the provider.
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Sep 4, 2026 in messaging, anonymity, metadata - Session drops phone numbers and central servers, Signal keeps both and encrypts everything else. What each one hides from whom, what Session gives up to get anonymity, and the single question that decides which of the two you actually need.
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Sep 4, 2026 in mobile, 2fa, account-security - A SIM swap moves your number to someone else's card, and every code sent by text follows it. What actually stops the attack at the carrier, why SMS two-factor is the wrong lock, and the ten minutes that decide whether you keep your accounts.
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Sep 4, 2026 in vpn, privacy, network - A kill switch cuts your internet the moment the VPN tunnel drops, so nothing leaves in the clear. What it protects, the gap between blocking one application and blocking the whole device, and how to test yours in two minutes instead of trusting the label.
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Sep 4, 2026 in vpn, privacy, network - Split tunneling sends some applications through the VPN and lets the rest use your ordinary connection. What it fixes, the three ways it quietly leaks, and the one question that tells you whether to turn it on.
Read more…Operating systems
Which secure OS fits which threat model - compartmentalisation vs amnesic vs Tor-routed.
Read the guides →Encryption
LUKS, BitLocker, FileVault and VeraCrypt - what each protects, and what it does not.
Read the guide →Hardening
Practical hardening built around the adversary you actually face.
Read the guide →