> For the complete documentation index, see [llms.txt](https://corpus-core.gitbook.io/pap-colibri-stateless/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://corpus-core.gitbook.io/pap-colibri-stateless/the-model/pragmatic-adaptive-privacy/privacy-application-layer.md).

# Privacy Application Layer

## Privacy Application Layer

PAP defines privacy requirements. The **Privacy Application Layer (PAL)** realizes them.

Applications specify Privacy Profiles. PAL translates these profiles into concrete execution strategies, selecting the appropriate transport mechanisms and content protection techniques based on the requested profile and the capabilities of the execution environment.

PAL is an orchestration layer, not a privacy mechanism. It remains independent of specific technologies. Existing and future mechanisms — Tor, Mixnets, query aggregation, over-fetching, PIR, ORAM — can all be integrated without changing PAP or application logic.

The architecture is structured as follows:

```
Application
      ▲
      │
Privacy Application Layer (PAL)
      ▲
      │
Verification Engine
      ▲
      │
RPC / Indexer / Prover Service
(Untrusted Data Sources)
```

Data is retrieved from untrusted providers. Verification happens locally. PAL operates above the verification layer and applies the selected Privacy Profile before exposing data to the application. Privacy and verifiability are therefore preserved simultaneously.

Applications define what privacy properties they require. PAL determines how these properties are achieved.