> ## Documentation Index
> Fetch the complete documentation index at: https://docs.go.gbgplc.com/llms.txt
> Use this file to discover all available pages before exploring further.

# NFC Chip Authentication

> Validate the authenticity of NFC-enabled identity documents in GBG GO using cryptographic chip checks against passive, active, and chip cloning attacks.

The **NFC Chip Authentication** module validates the authenticity of identity documents that contain an embedded NFC (Near Field Communication) chip.

This page contains documentation for the **NFC Chip Authentication** module, including its capabilities and the specific result values it returns.

## NFC Chip Authentication

The NFC Chip Authentication module performs different cryptographic checks against the document's embedded chip, each targeting a different threat vector. The overall authentication result aggregates these individual checks. If any single check fails, the overall result fails.

### Capabilities

The module returns the NFC Chip Authentication capability.

#### NFC Chip Authentication

This capability provides the aggregate outcome of all NFC chip authentication checks. It fails if any of the three individual authentication checks (passive, active, or chip) fails. This is the primary capability used in evaluation and routing logic.

| Value    | Description                                                                                                                               |
| -------- | ----------------------------------------------------------------------------------------------------------------------------------------- |
| `PASSED` | All individual authentication checks passed. The chip is genuine, the data is authentic and unmodified, and the chip has not been cloned. |
| `FAILED` | One or more individual authentication checks failed. The document's NFC chip could not be fully validated.                                |
| `ERROR`  | The overall authentication could not be completed due to a technical issue.                                                               |

## Input payload

The following is a sample payload used to submit NFC chip data to the **NFC Chip Authentication** module for processing.

```json JSON theme={null}
{
  "resourceId": "<resourceId>",
  "context": {
    "config": {
      "delivery": "api"
    },
    "subject": {
      "documents": [
        {
          "mrz": "<string>",
          "chip": {
            "lds": [
              {
                "name": "<string>",
                "data": "<base64-encoded string>"
              }
            ],
            "auth": [
              {
                "type": "<string>",
                "result": "<string>"
              }
            ]
          }
        }
      ]
    }
  }
}
```

| Field       | Required | Description                                                                                                                                                                   |
| ----------- | -------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `mrz`       | Yes      | The machine-readable zone string extracted from the document. Used to establish a secure communication channel with the chip.                                                 |
| `chip.lds`  | Yes      | An array of Logical Data Structure (LDS) entries read from the chip. Each entry contains a `name` identifying the data group and a base64-encoded `data` payload.             |
| `chip.auth` | Yes      | An array of authentication check results performed during the chip reading process. Each entry contains a `type` identifying the check and a `result` indicating its outcome. |

## Sample response

The following is a sample response for a successfully authenticated NFC chip.

```json JSON theme={null}
{
  "response": {
    "advice": {
      "authenticationResult": "PASSED",
      "activeAuthenticationResult": "PASSED",
      "passiveAuthenticationResult": "PASSED",
      "chipAuthenticationResult": "PASSED"
    },
    "outcome": "Passed"
  }
}
```