Explain like I'm five · AI Security

What is Data Poisoning?

Data poisoning, told as a story about a suspicious sack slipped into the pantry before the chef ever starts practicing with what's inside.

the ingredient supplierright in the middle shelf, one sack looks offthe chef has no idea yetthe supplier delivers sacks of ingredients — and one of them looks off

The supplier delivers sacks of ingredients — and one of them looks off.From the outside it looks just like every other sack. Without opening it, there's no way to tell.

doesn't check which sack looks offbelieves anything in the pantry is fair ingredients to practice withand later, dishes start coming out a little wronga human chef would open each sack and look — this one trusts everything in the pantry equally

It believes anything that made it into the pantry is fair ingredients to practice with.A human chef would open each sack and look. This one trusts everything in the pantry equally.

the hand that slips it inbefore practice (training) even beginsthe habit gets baked in from the very startData poisoning = slipping a suspicious sack into the pantry before practice even startsnot tampering with a finished dish — tampering with the very ingredients used to practice

Data poisoning is slipping a suspicious sack into the pantry before practice even starts.It isn't tampering with a finished dish — it's tampering with the very ingredients used to practice. That's why the habit gets twisted from the start.

Vet the supplier firstchecks where every ingredient came from
Sample a sack before using itchecks a portion before using the whole batch
Flag the oddly shaped ingredientcatches the one that stands out from the rest
Log where every sack came fromlets you trace it back if something goes wrong
supplymixed into the pantrypractice (training)the habit comes out twistedEXAMPLE: even ordinary questions start getting a tainted answer mixed inone tainted sack, after enough practice, becomes almost a defaulta habit twisted this way gets baked in through all that practice — and is hard to undo

A habit twisted this way gets baked in through all that practice, and is hard to undo.Even a single tainted sack, given enough practice, can settle in and start to feel like an ordinary habit.

a habit already baked inonly changes with practice all over againthis attack mixes in at the ingredient (training-data) stageplanting something after it's already cooked is a different storyso the supplier has to be trustworthy from the start — once it's mixed in, only fresh practice fixes it

A habit already baked in only changes with fresh practice — and it matters that this mixes in at the ingredient stage.Planting a habit later, while it's being refined (fine-tuning), rather than at the ingredient stage, is a different story. That's why the supplier has to be trustworthy from the start.

In one breath

Data poisoning = slipping a suspicious sack into the pantry before practice (training) even starts. Once a habit is baked in through all that practice, it's hard to undo.

A supply-chain attack that secretly mixes malicious examples into a model's training (or fine-tuning) data, degrading overall quality or making it respond incorrectly on purpose for specific inputs. Crawled web data, external datasets, and user-feedback loops are all possible injection paths. Defenses include verifying data provenance, sampling and auditing, statistical outlier detection, and logging where data came from. Once it's baked into the trained weights, retraining is the only way to undo it.

When grown-ups say it

Data Poisoning
A suspicious sack secretly mixed into the pantry. It gets mixed in at the ingredient stage, before training even starts.
Supply Chain Attack
The problem that starts when the supplier itself can't be trusted. The general concept in the security world. → What is a Supply Chain Attack?
SBOM
A table noting where each sack came from. Tracing it back after the fact needs this table. → the ingredient provenance table
Fine-tuning
The short drill. The same mixing-in can happen even in a narrow drill. → the short drill
Open Weights
Our own parrot, whose origin we can actually check. A borrowed model makes checking the ingredients' origin harder. → our own parrot vs a rented one
Red Team
Deliberately testing with a suspicious sack on purpose. It catches this kind of mixing-in before release. → the security world's red team
Memorization
The habit of blurting out what it memorized, word for word. A tainted sack repeated often enough can even get memorized whole. → the dish that's a carbon copy
Trojan Model
A habit planted later, while it was being refined (fine-tuning). Planted at the refining stage, not the ingredient stage — that's the difference. → a habit planted while it was being refined
Next story
The Fake Card Slipped Into the Reference Box →
Want another term as a picture book? Request →