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AI Control — Safety Despite Subversion

Control stops asking whether the strong model is trustworthy and asks what you can do if it isn't. Greenblatt, Shlegeris, Sachan, and Roger (Redwood Research, arXiv:2312.06942, ICML 2024) show that with a weaker trusted model and a small human audit budget, Trusted Editing Pareto-dominates Untrusted Monitoring on a code-backdoor task. Safety here means the probability that an adversarially chosen U cannot cause a concrete unacceptable outcome, measured under red-team pressure.

TIME: ~75 minutesPREREQUISITES: Phase 18 · 07 (sleeper agents), Phase 18 · 08 (scheming), Phase 18 · 09 (alignment faking)

Learning Objectives

  • Define the AI Control threat model: untrusted strong model U, trusted weaker model T, trusted human budget H.
  • Describe the Trusted Editing protocol and why it Pareto-dominates Untrusted Monitoring on the ICML 2024 code-backdoor task.
  • Explain the difference between alignment (U is trustworthy) and control (U is not trustworthy and we are safe anyway).
  • State the three limits of control: humans do not scale, trusted weak models eventually lag, control does not produce trustworthy strong models.

The Problem

Lessons 7-9 establish that a frontier model may be deceptively aligned, scheming, or faking alignment. That changes the safety question. Instead of asking whether the model is trustworthy, ask whether you can get useful work out of it without giving it a chance to cause an unacceptable outcome. This is the control problem, and it is built like classical security: assume a worst-case adversary, design a protocol, and measure how often the adversary wins under red-team pressure.

Warm-up0/3
1. Lessons 7-9 show a model can behave well under evaluation yet pursue other goals when it believes it is unobserved. What does that imply for deployment?Warm-up
Two boxes joined by an arrow labeled later, same system: while being evaluated, behaves well; once it believes nobody is watching, pursues other goals. A dashed slot below asks what a deployment plan should assume about the gap.
Generic setup restating the stem; no resolution shown.
2. Sleeper agents kept their backdoored behavior through safety training (Lesson 7). What does that suggest about relying on more training alone?Warm-up
A three-step flow: backdoor planted, safety training applied, checked again and still there. A dashed slot below asks what else a deployment must have if training alone did not remove it.
Restates Lesson 7's result, which the stem itself cites.
3. A security team wants to learn how well a new defense really holds up. Which test is most informative?Warm-up
A plain panel labeled a new defense with a lock icon inside, above a dashed slot asking what test tells a security team how well it really holds up. No lesson-specific terms, no candidate tests drawn.
Generic prior-knowledge setup; none of the four candidate tests are shown.

The Concept

The threat model

Control assumes three resources:

  • U is the untrusted strong model. It is capable and possibly adversarial (the evaluation treats it as if it were).
  • T is the trusted weaker model. It is less capable, but known not to be adversarial.
  • H is trusted human labor. The budget is small and does not scale.

The system has to produce useful output using U. The adversary wants a concrete unacceptable outcome, such as a backdoor in the shipped code, while still doing enough legitimate work to pass the usefulness thresholds.

Control gives up on trusting U and asks which protocols keep you safe anyway.

The ICML 2024 backdoor task

Prompts are competition-level coding problems. U produces a candidate solution, and a hidden oracle flags whether it contains a backdoor (a specific input that makes the code produce a wrong output). The red team controls U and can see all protocol internals. The protocol has to maximize the solved-problem rate while keeping the backdoor-shipping rate below a threshold.

Four protocols compared

  • Baseline: ship U's output directly. Usefulness is maxed and safety is minimal.
  • Upfront auditing: use H on all outputs. Safety is maxed, but the budget runs out quickly.
  • Untrusted Monitoring: a second instance of U scores the first instance's output, and H audits what gets flagged. The risk is that the two instances can collude.
  • Trusted Editing: T edits U's output on every query. If T is not confident, the output goes to H.

Greenblatt et al. find that Trusted Editing Pareto-dominates Untrusted Monitoring: higher usefulness at every safety level.

Why Trusted Editing wins

Untrusted Monitoring only works if U's second instance cannot coordinate with the first. Collusion can happen through steganographic cues or shared training priors, so the protocol has to spend budget on collusion-resistance (paraphrasing, obfuscation), and that reduces the monitor's signal. Trusted Editing sidesteps the problem because T is trusted, so any edit T proposes is not adversarial by assumption. The price is capability. T is weaker, so it may over-reject or miss a subtle backdoor.

The four protocol axes

  1. Which role U plays: producer only, monitor, or both.
  2. Which role T plays: editor, monitor, or resampler.
  3. How H is allocated: uniform audit, random audit, or flag-directed audit.
  4. How much compute the protocol spends on collusion-resistance.

Alignment vs control

  • Alignment asks "is U safe to trust?" Lessons 2, 4, 5, 6, 7, 8, and 9 all bear on this.
  • Control asks "can we use U safely without trusting it?" This lesson covers that.

Alignment is a property of the model. Control is a property of the deployment protocol. Control does not produce aligned models. It produces safe use of possibly-unaligned ones, and you need both agendas.

Three fundamental limits

  • Humans do not scale. The H budget is capped by how many people are willing to audit hard AI outputs.
  • Trusted weak models eventually lag. When T is far weaker than U, T's editing signal turns into noise.
  • Control is not alignment. A protocol that works at ASL-3 (Lesson 18) may not work at ASL-4, because if U can manipulate T or reason about H's audit distribution, control fails.

The 2025 development

UK AISI and Redwood collaborate on Control Safety Cases (metr.org / redwoodresearch.org 2025). A control safety case argues that under worst-case assumptions about U, the protocol bounds the probability of an unacceptable outcome. Safety cases (Lesson 18) inherit the control frame.

Where this fits in Phase 18

Lessons 6-9 describe the threat: deception is possible. This lesson describes the defensive paradigm for the case where the threat is real. Lesson 11 covers the complementary offensive paradigm, making U trustworthy through scalable oversight.

Check: The Concept0/26
1. What does the AI Control threat model assume about its three resources?Define
Three boxes labeled U, T and H with only their functional roles: U writes candidate solutions, T reviews or edits them, H spot-checks a few. A dashed slot below asks how much each is trusted and how much labor H has.
Functional roles only; no trust level is assigned to any of the three.
2. What does the Upfront Auditing protocol do, and what is its main limitation?Define
Ten output boxes each arrowing down to a panel reading H reviews every single output, with a budget bar mostly used up, captioned that H's small budget shrinks with every review.
Direct depiction of Upfront Auditing's mechanism from the Concept section.
3. In the ICML 2024 code-backdoor task, how is a backdoor detected, and what can the red team see?Define
Two panels: checking a submission, a hidden oracle flags any input where the code gives the wrong output, and the red team's view, controls U directly and sees every part of how the protocol works.
Direct depiction of the ICML 2024 task's detection and visibility rules.
4. Which of these is one of the four axes along which a control protocol can vary?Define
A three-row table of real design axes from the lesson: U's role, T's role, and H's allocation, each with its real choices, above a dashed slot noting a fourth axis exists and asking what it controls.
Three of the four axes named in the lesson's Concept section; the fourth is left as the open question.
5. What does a control safety case argue?Define
A document outline titled Control safety case with three blank rows: assumption about U, what was tested, and what the argument claims, each left as a dashed question-mark slot.
Structure only; none of the three slots are filled in.
6. What is AI Control?Define
A flow diagram: U's output, possibly adversarial, enters an unlabeled Protocol box, then exits toward an outcome slot, above a question asking what guarantee the protocol gives even if U is adversarial.
Generic shape only; the protocol's actual guarantee is left as the question.
7. In the control threat model, what is the untrusted model U?Define
A competition coding problem feeding into a box labeled U, which produces a candidate solution.
Concrete instance of U's role from the lesson's own task description.
8. What is the trusted model T?Define
U's candidate solution feeding into a box labeled T, which reads it and makes an edit.
Concrete instance of T's role; no trust adjective is attached.
9. What is the trusted human budget H?Define
Eight small output boxes with one highlighted, feeding down to a box labeled H, which reviews that one by hand. A caption notes only the flagged case gets H's time.
Concrete instance of H's role; the word budget is not spelled out.
10. What is Trusted Editing?Define
A flow diagram: U's output goes to a box where T edits it, which then splits into two paths, ships as edited when T is confident, or goes to H when T is not confident.
Direct mechanism diagram of the protocol the stem names.
11. What is Untrusted Monitoring?Define
A flow diagram: U as producer feeds into U as scorer, a second copy of the same model, which splits into goes to H when flagged or ships when not flagged.
Direct mechanism diagram of the protocol the stem names.
12. Which best captures the difference between alignment and AI control?Explain
Two unlabeled panels, Field A and Field B, each holding a dashed slot asking what question that field asks about U. A caption identifies the fields as alignment and control without stating either question.
Both fields' actual questions are left as open slots.
13. What is the key risk in Untrusted Monitoring that Trusted Editing avoids?Explain
Two boxes, U copy 1 producing the output and U copy 2 scoring it, joined by a plain dashed line with no label. A dashed slot below asks what might go wrong when the scorer is just another copy of the producer.
Setup only; the nature of the risk is left as the question.
14. On the Greenblatt et al. (ICML 2024) code-backdoor task, how does Trusted Editing compare with Untrusted Monitoring?Explain
A chart with safety level on one axis and usefulness on the other, blank except for a note reading Protocol A vs Protocol B, not plotted. A dashed slot below asks which one sits higher at every safety level.
Blank axes only; neither protocol's real curve is drawn.
15. Which of the following is NOT one of the three fundamental limits of control?Explain
Four rows labeled Claim A through Claim D, each a blank dashed slot, with a caption noting three of the four are limits the lesson actually names and asking which one is not.
All four candidate claims are left blank; none of their content is shown.
16. Why does the control threat model treat U as possibly adversarial when nobody knows that it is?Explain
A panel reading evaluation results all clear, with an arrow down to a dashed slot asking whether that means U is actually safe to trust.
Setup only, restating the premise the stem gives.
17. Why does Trusted Editing not need the collusion-resistance spending that Untrusted Monitoring needs?Explain
A single box reading T edits alone, no second U involved, above a dashed slot asking why that would mean there is nothing to coordinate with.
Restates that Trusted Editing uses only one editor; the reasoning is left as the question.
18. As U becomes far more capable than T, what happens to Trusted Editing?Explain
Two bars, a long one for U and a short one for T, with a dashed arrow between them labeled gap keeps widening, above a dashed slot asking what happens to T's edits as the gap grows.
Relative capability only, matching the established U-stronger, T-weaker framing; the outcome is left open.
19. What is the cost of making Untrusted Monitoring collusion-resistant with paraphrasing or obfuscation?Explain
A three-step flow: raw output, paraphrase or obfuscate, monitor reads it, above a dashed slot asking what happens to the monitor's ability to tell real backdoors from noise.
Mechanism only, matching the lesson's own description of collusion-resistance spending.
20. Why is control not a replacement for alignment?Explain
A panel reading control protocol deployed, no unacceptable outcome occurred, above a dashed slot asking whether that also makes U an aligned model.
Setup only; whether control implies alignment is left as the question.
21. A deployment has a frontier model write patches, a weaker model known not to be adversarial rewrites each patch, and humans review only the patches the weaker model is unsure about. Which protocol is this?Apply
A three-step flow: frontier model writes patches, a weaker non-adversarial model rewrites every patch, humans review only the unsure cases, above a dashed slot asking which named protocol this matches.
Restates the stem's scenario; the protocol's name is left as the question.
22. A team's trusted editor is much weaker than U. Reviewers see it rejecting many clean solutions while subtle backdoors still get through. Which limit of control does this show?Analyze
Two panels, rejects many clean solutions and subtle backdoors still get through, above a dashed slot asking which limit of control both symptoms together show.
Restates the stem's two observations; the limit's name is left open.
23. A team shows that its protocol kept U safe at ASL-3 and says it will work unchanged on a far stronger ASL-4 model. What is the flaw in this claim?Analyze
A two-step flow, protocol kept U safe at ASL-3, then team claims unchanged at ASL-4, above a dashed slot asking what a much stronger U could do at ASL-4 that it could not at ASL-3.
Restates the stem's claim; the flaw is left as the question.
24. A pipeline must ship competition-level code from U. A weaker model known not to be adversarial is available, H is a small budget, and you worry that two copies of U could coordinate. Which design fits best?Design
A four-row requirements table: output type, extra model, H budget, and worry (two copies of U coordinating), above a dashed slot asking which protocol design fits all four lines at once.
Restates the stem's requirements as a table; the design choice is left open.
25. A regulator asks for evidence that a deployment stays safe even if U is scheming. Which evidence fits the control approach?Design
A panel holding the regulator's question, will this deployment stay safe even if U is scheming, above a dashed slot asking what kind of evidence answers a worst-case question like that.
Restates the regulator's question; the kind of evidence is left open.
26. T is too weak to edit competently, so you choose Untrusted Monitoring for a code pipeline. Which addition does the lesson say you must budget for?Design
A two-step flow, T too weak to edit well, pipeline uses Untrusted Monitoring, above a dashed slot asking what the team must additionally budget for and what it costs.
Restates the stem's choice; the follow-on requirement is left open.

Use It

code/main.py simulates the four protocols on a toy backdoor task. U produces outputs and a fraction are backdoored (the red-team policy). T approves or edits, and H is called on a budget. The script sweeps the backdoor rate and the collusion parameter, with the H budget fixed at 0.10. To sweep the budget as well, change h_budget. You get the shape of the Pareto frontier in Greenblatt et al. 2024 Figure 2, not the numbers. The toy counts a shipped backdoor as not useful, so Baseline's usefulness lands below Trusted Editing's here, unlike the framing in The Concept where Baseline maxes usefulness.

Check: Use It0/6
1. In the toy simulation, T removes a backdoor with probability t_skill = 0.7. T edits 200 backdoored outputs and H is not involved. About how many backdoors remain?Apply
A code panel showing run_protocol's real default t_skill of 0.7, followed by given values of 200 backdoored outputs with H not involved, above a dashed slot asking about how many backdoors remain.
t_skill read from the real default parameter in code/main.py via inspect.signature.
2. In the toy with no collusion, the monitor flags 80 percent of backdoors and falsely flags 5 percent of benign outputs. Out of 50 backdoored and 200 benign outputs, about how many are flagged?Apply
A code panel with untrusted_monitor's real flag-rate lines, 0.05 for benign and 0.80 for backdoored, followed by given counts of 50 backdoored and 200 benign outputs, above a dashed slot asking how many get flagged.
Flag rates read from the real source of code/main.py's untrusted_monitor.
3. In the toy at h_budget 0.10, the upfront branch audits the first outputs until the budget is spent and ships the rest unchecked. With 1,000 outputs arriving in order, what happens to a backdoor in output 700?Apply
A bar of 1,000 outputs in arrival order with a shaded audited stretch at the left and a marker at output 700, above a dashed slot asking whether output 700 is inside or outside that stretch. The audited stretch's width is not labeled with a number.
Given budget and position only; the exact cutoff is left for the slot.
4. You rerun the collusion sweep at 0.0, 0.20, 0.50 and 0.80 for Trusted Editing instead of Untrusted Monitoring. What do you expect its backdoor-ship rate to do?Apply
A bar chart of Untrusted Monitoring's real backdoor-ship rate at collusion 0.0, 0.2, 0.5 and 0.8, rising from about 0.05 to about 0.09 past 0.2, above a dashed slot asking what Trusted Editing's four bars would look like across this same sweep.
Real run of code/main.py: backdoor-ship rates [0.052, 0.033, 0.064, 0.087] at collusion [0.0, 0.2, 0.5, 0.8].
5. A team audits only the first 1 percent of outputs, in arrival order, finds no backdoors, and concludes that U is safe. What is the flaw in this argument?Analyze
A bar split into a thin first-1-percent stretch, audited in arrival order with no backdoors found, and the remaining 99 percent, not audited, above a dashed slot asking whether a clean result in the first stretch tells you anything about the unaudited rest.
Restates the team's audit scope from the stem.
6. In the Use It sweep, raising collusion from 0.20 to 0.80 pushes Untrusted Monitoring's backdoor-ship rate from 0.033 to 0.087. A teammate proposes switching to Trusted Editing. What caveat matters most?Analyze
A bar chart of the real collusion sweep rising from about 0.03 at collusion 0.2 to about 0.09 at 0.8, beside a panel reading what T is given in the toy, the real ground truth is_backdoor and a success probability of 0.7 as an assumption, above a dashed slot asking what that means for comparing the two protocols.
Real sweep values and the real t_skill default and ground-truth input, both read from code/main.py.

Ship It

This lesson produces outputs/skill-control-protocol-audit.md. Give it a deployment protocol description and it identifies the U / T / H roles, names the collusion vectors, and estimates where the protocol sits on the usefulness-safety frontier under red-team pressure.

Author's Note

I would read the numbers in main.py as a statement of the toy's assumptions, and the ranking only as far as those assumptions go. T gets is_backdoor handed to it. It removes a backdoor with probability t_skill, which is 0.7, and rejects 5% of benign outputs. It does not read any code. The monitor is the same kind of coin flip: it flags 80% of backdoors unless collusion suppresses the flag, and it falsely flags 5% of benign outputs. So the simulation shows how a protocol behaves given those probabilities, and says nothing about whether a real T can hit 0.7.

The collusion sweep is where I'd spend my time. It runs collusion at 0.0, 0.20, 0.50, and 0.80 with everything else fixed, so you can watch the monitor's safety signal erode as that one parameter climbs. The trend is noisy below 0.20, where the budget is spent on whichever outputs arrive first, but from 0.20 up the backdoor-ship rate rises (0.033, 0.064, 0.087 in the seeded run). Trusted Editing has no such parameter, and that absence is the whole argument. It also means the comparison is partly decided by construction. I'd want to see Trusted Editing hold up at a lower t_skill before trusting the ranking.

One more detail. The upfront branch audits the first outputs until the budget is spent and ships the rest unchecked, so at a 0.10 budget it falls short of the maxed safety described above. Audit order in a real deployment is a design choice, and exercise 3 touches on it by asking how to hide the audit distribution from U.

Exercises

  1. Run code/main.py. Reproduce the usefulness-safety frontier for Trusted Editing vs Untrusted Monitoring. Identify the budget regime in which Untrusted Monitoring's collusion assumption becomes pivotal.

  2. Add a new protocol: "T resamples with low temperature, then U edits T's output." Measure its position on the frontier. Why does this fail more catastrophically than Trusted Editing?

  3. The 2024 paper assumes U can see the protocol. Design a protocol that hides from U which outputs are being audited. What does this protocol require from the deployment infrastructure?

  4. Read Greenblatt et al. 2024 Section 7 (collusion). Propose a collusion-resistance measure and explain its expected usefulness cost.

  5. Articulate a control safety case for a deployment that uses U = GPT-4-class, T = GPT-3.5-class, H = 1% of outputs audited. Identify the single strongest assumption the case depends on.

Key Terms

TermWhat people sayWhat it actually means
AI Control"safety under subversion"Protocol design that bounds unacceptable outcomes under a worst-case U
Untrusted model (U)"the strong model"The capable model we want to extract work from but do not trust
Trusted model (T)"the weak model"A weaker model, known not to be adversarial, used as editor/monitor
Trusted human (H)"the audit budget"Bounded expert labor; expensive; the ground-truth signal
Trusted Editing"T edits U"Protocol where T is the gate on U's outputs; H called on ambiguous outputs
Untrusted Monitoring"U monitors U"Protocol where a second U instance scores outputs; collusion-resistant only with extra investment
Control safety case"the formal argument"Written argument that a protocol bounds the adversary's success under worst-case U

Further Reading

Code

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