secure-os wrote
Sep 6, 2026 in ssh, authentication, linux - The message says publickey, so people regenerate keys. That is almost never the problem. In descending order of frequency: the wrong key was offered, the file permissions are too open, the username is wrong, or the server does not allow that method. How to find out in one command.
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Sep 6, 2026 in headers, web security, csp - Six response headers are the ones every hardening guide lists. We measured them on 336 public organisations: 78 of the 301 that answered send none of the six, and Permissions-Policy is missing on eight sites out of ten. The list, in the order worth deploying it.
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Sep 6, 2026 in windows 11, copilot, privacy - Hiding the button, disabling the feature by policy, and uninstalling the package are three different things with three different outcomes. Which one survives an update, which one needs Pro, and the honest answer about what still runs afterwards.
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Sep 6, 2026 in phone, scams, privacy - Blocking numbers one by one cannot keep up with software that changes number every call. What actually reduces the volume is carrier filtering, a setting already on your phone, and one habit that costs nothing. Also: why answering at all makes it worse.
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Sep 6, 2026 in phone, theft, accounts - Locating it is not the first thing to do, and it is rarely the useful one. What matters in the first hour is the accounts the phone was signed into and the SIM that receives your codes. The order that limits the damage, and the two steps to take before it ever happens.
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Sep 5, 2026 in encryption, windows, threat-model - On most consumer Windows PCs the BitLocker recovery key is uploaded to the Microsoft account used at setup. That is why people find it, and it is also the part of the threat model most users never agreed to. Where it lives, how to check, and what changes if you remove it.
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Sep 5, 2026 in windows, privacy, telemetry - The settings that reduce Windows 11 telemetry are real, and the tools that promise to remove it entirely are mostly not. What Required diagnostic data covers, which switches change something measurable, and where the honest limit sits.
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Sep 5, 2026 in linux, forensics, incident-response - Every checklist gives you the same commands. Almost none of them tell you that running those commands on the suspect machine is exactly what an attacker prepared for. Here is what to look at, in the order that still tells you something.
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Sep 5, 2026 in wifi, privacy, network - A rogue hotspot looks exactly like the real one, because it is allowed to. The name, the signal and the captive portal can all be copied in minutes. Here are the signals that actually distinguish them, and the one habit that makes the question stop mattering.
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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.
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 →