Glossary

What is prompt injection?

Prompt injection is an attack where untrusted input manipulates an LLM into ignoring its original instructions or revealing protected data.

Definition

Prompt injection is an attack where untrusted input manipulates an LLM into ignoring its original instructions or revealing protected data.

Definition

Prompt injection — short definition

Why it matters

Why this matters

Any AI feature that mixes user input with system instructions is at risk. Prompt injection can leak system prompts, escalate privileges, or exfiltrate context.

Any AI feature that mixes user input with system instructions is at risk. Prompt injection can leak system prompts, escalate privileges, or exfiltrate context.

How it works

How it works

From top to bottom: governance and policy, application minimization, a gateway that masks and routes, the BYOK provider boundary, and provider-side controls.01 · Governance & policyDocuments intent02 · Application minimizationDrops fields upstream03 · Gateway: mask + route + retainIn the request path04 · BYOK provider boundaryCustomer owns the key05 · Provider-side controlsTier, retention, region
Layered AI controlsNo single layer is sufficient. Each compensates for the others' gaps.

Framework

Prompt injection process

  1. 01

    Untrusted input arrives

    User input or third-party content reaches the prompt context.

  2. 02

    Instructions are overridden

    Crafted text persuades the model to ignore prior instructions.

  3. 03

    Defense layers run

    Prompt security at the gateway plus PII masking limit blast radius.

Implementation

Learn how this works in Privian

From definition to implementation, docs and architecture — the same idea at different layers.

FAQ

Frequently asked questions

How is prompt injection different from SQL injection?
Both abuse the lack of a hard boundary between code and data. In prompt injection the 'code' is natural-language instructions, which makes detection harder.
Can prompt injection be fully prevented?
No single technique fully prevents it. The practical answer is layered defense: input handling, prompt security at the gateway, and minimizing what sensitive data is ever in scope.
Does masking PII help against prompt injection?
Yes — even if an attacker bypasses instruction guarding, masked values mean the model never had access to the raw data in the first place.

Where to go next

From definition to implementation

This entry is part of the Privian content library. If you are evaluating how this concept is implemented in practice, the links below are the most direct paths.

Related product

Prompt Security in Privian

Privian focuses on prompt privacy controls in the request path. It does not currently claim prompt-injection defense.

Open product page →