Least Privilege

Confining an agent's commands to a limited environment, so that a mistaken or hijacked action can only damage what the sandbox allows it to reach.

An agent run that continues without a person watching, started by a schedule, an event, or a handoff, and reports its results when done.

A many-player elimination format that uses a shrinking play area to force an ending the players would otherwise avoid.

Small programs that modify the browser and the pages it shows, from bookmarklets and userscripts to ad blockers, with access broad enough to make them a standing security risk.

Cryptographic attestation of an originating telephone number, and why spoofed calls survive it.

Rebasing a process's idea of the filesystem root, the oldest and shallowest form of Unix process isolation.

The shared buffer behind cut, copy, and paste, invented at Xerox PARC, which offers data in several formats at once and has become a channel for snooping and for commands that paste differently from how they looked.

Cryptographically attesting who produced a binary, and the operating-system checks built on it.

Fraud that obtains trust first, so the victim hands over the money themselves.

Tricking a logged-in user's browser into sending a state-changing request to another site, which works because the browser attaches that site's cookies automatically.

Special files that represent hardware and kernel services, letting programs read a disk, a mouse, or a stream of random bytes with the same calls they use on ordinary files.

The program that sits between applications and the screen, keyboard, and mouse, deciding what is drawn where and who receives input. On Linux it is moving from X11 to Wayland.

The distributed directory translating names to addresses, and the layer where propagation delays live.

A named value in a process's environment, inherited by its children — the standard configuration channel.

A SIM soldered into the device and provisioned over the air, with profiles downloaded rather than cards swapped.

The Unix scheme of read, write, and execute rights for a file's owner, group, and everyone else, and the extensions that patch its gaps.

A filter that allows or blocks network traffic by rule, the oldest perimeter defense, and less sufficient on its own than it used to be.

A rule constraining what a model may do, enforced by prompt, schema, or surrounding code.

A whole web page embedded inside another, the web's main isolation boundary for ads, payments, and widgets, and the messaging and sandboxing rules that govern it.

The channels separate processes use to exchange data and signals, from pipes and sockets to shared memory, a necessity because each process is walled off in its own memory and a frequent route for sandbox escapes.

Everyday objects with network connections, from thermostats and light bulbs to industrial sensors, notorious for weak security, dependence on vendor clouds, and devices that outlive the companies supporting them.

The kernel feature that gives a process its own private view of a global resource — the foundation containers are built from.

An open protocol for exposing tools, data, and prompts to AI applications through a uniform interface.

Storage that keeps whole files as objects addressed by key in a flat namespace over HTTP, cheap and nearly limitless, which became the foundation for backups, media, and data lakes.

Any information that relates to an identifiable person, why it is broader than names and emails, and the engineering habits that privacy law now expects.

Untrusted content that reaches a model's context and is treated as instruction.

The browser rule isolating documents by scheme, host, and port, and the mechanisms for relaxing it.

Storing, distributing, and rotating credentials without embedding them in code or history.

Tricking a server into making requests on an attacker's behalf, reaching internal services and cloud credential endpoints that the attacker could never reach directly, behind some of the largest cloud breaches.

An attack in which user input is pasted into a database query and gets run as code, prevented by keeping the query and its data in separate channels.

A block of IP addresses that share a common prefix, written in CIDR notation such as 192.168.1.0/24, which decides what a device can reach directly and what it must send through a router.

The all-powerful root account on Unix systems, how sudo hands out its power temporarily, and why both attackers and good security design revolve around who gets it.

Protecting against compromise arriving through the code and tooling a project depends on.

The doorway through which a program asks the operating system kernel to do anything privileged, from reading a file to starting a process.

A structured way of asking what could go wrong with a system's security before an attacker answers it, by drawing where data flows, marking where trust changes, and walking each crossing through a list of threats.

A race where a program checks a condition and then acts on it, but the world changes in between, the root of classic file-permission exploits and of double-spending bugs in web applications.

An encrypted tunnel that presents a remote network as local, and the narrow set of things a commercial one actually hides.