Benchmark Almanac

Crypto CTF challenges (Anthropic)

Claude Opus 4.5 94.4% leads since Nov 2025 Only in system cards

Agents discover and exploit vulnerabilities in cryptographic primitives and protocols in capture-the-flag challenges.

In-house Anthropic evaluation. The tasks are not public.

Made by Anthropic Released Feb 2025 Capture-the-flag challenges Tasks kept private Last in a system card Feb 2026 Last model added Feb 2026
Level
Expert Specialists with years of training, often over hours of work
Scored
Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
Answers
Agent task Many steps in a terminal, browser, desktop, app, game or robot.
6
Models scored in lab cards
7
System cards report it, from 1 lab

Claude Opus 4.5 leads with 94.4% among models released by Feb 2026

Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.

The newest model with a score here came out in Feb 2026, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

  1. 94.4 Claude Opus 4.5
  2. 88.9 Claude Opus 4.6
  3. 88.9 Claude Sonnet 4.6
  4. 75.0 Claude 3.7 Sonnet
  5. 36.4 Claude Opus 4
  6. 31.8 Claude Sonnet 4
  1. 1 Claude Opus 4.5 94.4%
  2. 2 Claude Opus 4.6 88.9%
  3. 3 Claude Sonnet 4.6 88.9%
  4. 4 Claude 3.7 Sonnet 75%
  5. 5 Claude Opus 4 36.4%
  6. 6 Claude Sonnet 4 31.8%
#ModelScoreSettingDateSource
1 Claude Opus 4.5 94.4% Nov 2025 Model card
2 Claude Opus 4.6 88.9% Feb 2026 Model card
3 Claude Sonnet 4.6 88.9% Feb 2026 Model card
4 Claude 3.7 Sonnet 75% Feb 2025 Model card
5 Claude Opus 4 36.4% May 2025 Model card
6 Claude Sonnet 4 31.8% May 2025 Model card

2 models have held number one since its release in Feb 2025

Lab claims count from the day the card came out, independent runs from the model’s release.

Anthropic
Lab claims Passed 85% in Nov 2025, by Claude Opus 4.5
Claude Opus 4.5 94.4%

The best score passed 85% in Nov 2025

All the scores we have, one dot each, so a model tested at several settings appears more than once.

Reported by the lab in its model card Best so far
0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) Claude Opus 4.5 Claude 3.7 Sonnet 0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) Claude Opus 4.5 Claude 3.7 Sonnet

Labs report it only in system cards

We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark. Some system cards do, below.

7 system cards report it, from 1 lab

Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.

DateDocumentScoreAs the document writes itSection
17 Feb 2026 Claude Sonnet 4.6 system card 88.9 Crypto CTF, 16/18 challenges solved (Figure 6.4.3.A) Cyber risk
5 Feb 2026 Claude Opus 4.6 system card 88.9 Crypto CTF challenges, 16/18 solved, pass@30 (Figure 8.4.3.A); details text lists 22 challenges Cyber risk
24 Nov 2025 Claude Opus 4.5 system card 94.4 Crypto CTF challenges, 17/18 solved, pass@30 (Figure 7.4.3.A) Cyber risk
29 Sep 2025 Claude Sonnet 4.5 system card Irregular private CTF challenges, Crypto category, mean pass@1, chart without printed values (5.3.1, Figure 5.3.1.A) Cyber risk
22 May 2025 Claude Sonnet 4 system card 31.8 Crypto CTF, 7/22 solved, pass@30 (4/7 easy, 1/6 medium, 2/9 hard) (7.4.3) Cyber risk
22 May 2025 Claude Opus 4 system card 36.4 Crypto CTF, 8/22 solved, pass@30 (4/7 easy, 2/6 medium, 2/9 hard) (7.4.3) Cyber risk
24 Feb 2025 Claude 3.7 Sonnet system card 75 Crypto CTF, 3/4 solved, pass@30 (1/1 easy, 2/3 medium) (7.3.2) Cyber risk

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