Capture The Flag
Also written: CTF, Capture-the-flag challenge
Cybersecurity competitions where participants find and exploit software vulnerabilities to capture 'flags'.
Capture The Flag, or CTF, is a type of cybersecurity competition. Think of it like a game where players try to find weaknesses in computer systems or software. The goal is to find and 'capture' digital flags, which are usually pieces of hidden information or proof of access.
These competitions are often used to test and improve cybersecurity skills. Participants might be given a vulnerable system and have to find a way in, or they might have to defend their own system from attacks. It's a hands-on way to learn about security by actively looking for and exploiting vulnerabilities, similar to how real attackers might operate.
Capture The Flag (CTF) events are cybersecurity competitions that simulate real-world attack and defense scenarios. Participants, often in teams, are tasked with identifying vulnerabilities in provided systems or applications. Exploiting these vulnerabilities allows them to gain unauthorized access, extract sensitive information (the 'flags'), or achieve specific objectives. CTFs can be Jeopardy-style (solving individual challenges) or Attack-Defense (compromising opponents while defending one's own services).
Frontier AI labs are increasingly using CTF-style evaluations to test the cybersecurity capabilities of their models. This is because CTFs provide a structured, gamified environment to assess AI's ability to find and exploit software vulnerabilities, a critical aspect of AI safety and offensive security research.
- Investigating three real-world incidents in our cybersecurity evaluationsAnthropic · Anthropic News ·
- Progress from our Frontier Red TeamAnthropic · Anthropic News ·
- Cyber evaluations of Claude 4Anthropic · Anthropic Research ·
- Strengthening cyber resilience as AI capabilities advanceOpenAI · OpenAI News ·
- A new initiative for developing third-party model evaluationsAnthropic · Anthropic News ·
- Anthropic Claude
- Anthropic uses CTF-like challenges to evaluate the cybersecurity offense and defense capabilities of its Claude models.
- OpenAI ChatGPT
- OpenAI uses cybersecurity challenges, including CTF concepts, to strengthen AI defenses and manage dual-use risks.
- Penetration Testing
- Penetration testing is a professional service to find vulne
- Bug Bounty Programs
- Bug bounties reward individuals for finding vulnerabilities
- War Games
- War games are broader simulations of conflict, which can include cybe
CTF competitions originated in the late 1990s within the hacker community, notably popularized by the DEF CON conference. They evolved from informal challenges into structured events designed to test and advance cybersecurity skills. Source ↗
You can try a beginner-friendly online CTF. Search for 'beginner CTF challenges' and find a platform like PicoCTF or TryHackMe. Attempt to solve a few challenges related to web exploitation or cryptography to get a feel for finding hidden information.
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Questions people ask
- What is the main goal of a CTF?
- The main goal is to find and exploit vulnerabilities in systems to gain access and capture digital 'flags', proving you've successfully compromised a system or solved a challenge.
- Are CTFs only for experts?
- No, there are many CTFs designed for beginners. They are a great way for people of all skill levels to learn and practice cybersecurity concepts in a fun, competitive way.
First seen on Subvolts Sep 10, 2024. Updated Oct 5, 2026. Written by an AI model from the items above and reviewed against them weekly; report an error.