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

# Redact/mask value

export const entity_0 = "redact/mask value processing rule"

The redact/mask value [processing rule](/ingest/pipeline/processing-rules) obscures all
or part of a specified key's value by replacing the original string with a series of
repeated characters.

## Configuration parameters

Use the parameters in this section to configure the {entity_0}. The
Telemetry Pipeline web interface uses the items in the **Name** column to
describe these parameters. [Pipeline configuration files](/ingest/pipeline/v2/configure/config-files)
use the items in the **Key** column as YAML keys.

| Name                    | Key           | Description                                                                                                                                                                                                                                                                 | Default      |
| ----------------------- | ------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------ |
| **Key**                 | `key`         | Required. The key whose value to redact. The value of this key must be a string and not a number, Boolean, array, or object. You can also use [record accessor syntax](/ingest/pipeline/processing-rules#record-accessor-syntax) to reference keys nested within an object. | *none*       |
| **Regex**               | `regex`       | Required. The regular expression that determines which strings to redact. You can use this parameter to selectively redact certain strings while other parts of **Key** intact. To redact the entire value of **Key**, use the regular expression `^.+$`.                   | *none*       |
| **Replacement**         | `replaceChar` | Required. The string that replaces any redacted characters in the value of **Key**.                                                                                                                                                                                         | `*`          |
| **Regex engine**        | `regexEngine` | Required. The [engine](/ingest/pipeline/processing-rules#regex-engines) to parse your regular expression. Accepted values: `GNU`, `Oniguruma`, `PCRE2`, `POSIX`, `TRE`.                                                                                                     | `PCRE2`      |
| **Match case** checkbox | `matchCase`   | Indicates whether the regular expression is case-sensitive.                                                                                                                                                                                                                 | Not selected |
| **Comment**             | `comment`     | A custom note or description of the rule's function. This text is displayed next to the rule's name in the **Actions** list in the processing rules interface.                                                                                                              | *none*       |

## Examples

Using the redact/mask value rule lets you remove private or sensitive information
from your telemetry data.

### Full redaction

You can obscure the entire value of a specified key. For example, given
this sample log data:

```json theme={null}
{"timestamp":"2023-03-28T09:08:41.64283645Z","user":{"device":"mobile","ip":"149.206.93.24"},"page_id":30,"action":"purchase"}
{"timestamp":"2023-03-28T09:08:42.643343109Z","user":{"device":"desktop","ip":"107.30.35.78"},"page_id":10,"action":"purchase"}
{"timestamp":"2023-03-28T09:08:48.643600498Z","user":{"device":"desktop","ip":"255.255.239.8"},"page_id":50,"action":"click"}
{"timestamp":"2023-03-28T09:08:50.643773688Z","user":{"device":"mobile","ip":"166.128.199.193"},"page_id":40,"action":"purchase"}
{"timestamp":"2023-03-28T09:08:51.643932272Z","user":{"device":"other","ip":"212.96.55.27"},"page_id":30,"action":"purchase"}
{"timestamp":"2023-03-28T09:08:56.644080944Z","user":{"device":"mobile","ip":"18.87.158.235"},"page_id":40,"action":"click"}
{"timestamp":"2023-03-28T09:09:03.64425954Z","user":{"device":"desktop","ip":"200.101.159.250"},"page_id":30,"action":"click"}
{"timestamp":"2023-03-28T09:09:03.644317046Z","user":{"device":"desktop","ip":"95.208.154.180"},"page_id":20,"action":"view"}
{"timestamp":"2023-03-28T09:09:10.64447719Z","user":{"device":"desktop","ip":"227.14.218.76"},"page_id":50,"action":"purchase"}
{"timestamp":"2023-03-28T09:09:17.644810963Z","user":{"device":"other","ip":"158.229.53.77"},"page_id":10,"action":"view"}
{"timestamp":"2023-03-28T09:09:20.644994805Z","user":{"device":"mobile","ip":"48.30.70.51"},"page_id":50,"action":"view"}
```

A processing rule with the **Key** value `$user.ip`, the **Regex** value `^.+$`,
and the **Replacement** value `0` returns the following result:

```json theme={null}
{"user":{"ip":"0000000000000","device":"mobile"},"timestamp":"2023-03-28T09:08:41.64283645Z","action":"purchase","page_id":30}
{"user":{"ip":"000000000000","device":"desktop"},"timestamp":"2023-03-28T09:08:42.643343109Z","action":"purchase","page_id":10}
{"user":{"ip":"0000000000000","device":"desktop"},"timestamp":"2023-03-28T09:08:48.643600498Z","action":"click","page_id":50}
{"user":{"ip":"000000000000000","device":"mobile"},"timestamp":"2023-03-28T09:08:50.643773688Z","action":"purchase","page_id":40}
{"user":{"ip":"000000000000","device":"other"},"timestamp":"2023-03-28T09:08:51.643932272Z","action":"purchase","page_id":30}
{"user":{"ip":"0000000000000","device":"mobile"},"timestamp":"2023-03-28T09:08:56.644080944Z","action":"click","page_id":40}
{"user":{"ip":"000000000000000","device":"desktop"},"timestamp":"2023-03-28T09:09:03.64425954Z","action":"click","page_id":30}
{"user":{"ip":"00000000000000","device":"desktop"},"timestamp":"2023-03-28T09:09:03.644317046Z","action":"view","page_id":20}
{"user":{"ip":"0000000000000","device":"desktop"},"timestamp":"2023-03-28T09:09:10.64447719Z","action":"purchase","page_id":50}
{"user":{"ip":"0000000000000","device":"other"},"timestamp":"2023-03-28T09:09:17.644810963Z","action":"view","page_id":10}
{"user":{"ip":"00000000000","device":"mobile"},"timestamp":"2023-03-28T09:09:20.644994805Z","action":"view","page_id":50}
```

This rule redacted each user's IP address by replacing the value of `ip` with a
string of zeroes.

### Selective redaction

You can also redact specific strings while leaving other strings intact. For example,
given this sample log data:

```json theme={null}
{"timestamp":"2023-03-28T09:08:41.64283645Z","user_id":3,"page_id":30,"action":"purchase"}
{"timestamp":"2023-03-28T09:08:42.643343109Z","user_id":4,"page_id":10,"action":"purchase"}
{"timestamp":"2023-03-28T09:08:48.643600498Z","user_id":1,"page_id":50,"action":"click"}
{"timestamp":"2023-03-28T09:08:50.643773688Z","user_id":5,"page_id":40,"action":"purchase"}
{"timestamp":"2023-03-28T09:08:51.643932272Z","user_id":1,"page_id":30,"action":"purchase"}
{"timestamp":"2023-03-28T09:08:56.644080944Z","user_id":2,"page_id":40,"action":"click"}
{"timestamp":"2023-03-28T09:09:03.64425954Z","user_id":3,"page_id":30,"action":"click"}
{"timestamp":"2023-03-28T09:09:03.644317046Z","user_id":1,"page_id":20,"action":"view"}
{"timestamp":"2023-03-28T09:09:10.64447719Z","user_id":2,"page_id":50,"action":"purchase"}
{"timestamp":"2023-03-28T09:09:17.644810963Z","user_id":2,"page_id":10,"action":"view"}
{"timestamp":"2023-03-28T09:09:20.644994805Z","user_id":1,"page_id":50,"action":"view"}
```

A processing rule with the **Key** value `action`, the **Regex** value `purchase`,
and the **Replacement** value `*` returns the following result:

```json theme={null}
{"action":"********","timestamp":"2023-03-28T09:08:41.64283645Z","user_id":3,"page_id":30}
{"action":"********","timestamp":"2023-03-28T09:08:42.643343109Z","user_id":4,"page_id":10}
{"action":"click","timestamp":"2023-03-28T09:08:48.643600498Z","user_id":1,"page_id":50}
{"action":"********","timestamp":"2023-03-28T09:08:50.643773688Z","user_id":5,"page_id":40}
{"action":"********","timestamp":"2023-03-28T09:08:51.643932272Z","user_id":1,"page_id":30}
{"action":"click","timestamp":"2023-03-28T09:08:56.644080944Z","user_id":2,"page_id":40}
{"action":"click","timestamp":"2023-03-28T09:09:03.64425954Z","user_id":3,"page_id":30}
{"action":"view","timestamp":"2023-03-28T09:09:03.644317046Z","user_id":1,"page_id":20}
{"action":"********","timestamp":"2023-03-28T09:09:10.64447719Z","user_id":2,"page_id":50}
{"action":"view","timestamp":"2023-03-28T09:09:17.644810963Z","user_id":2,"page_id":10}
{"action":"view","timestamp":"2023-03-28T09:09:20.644994805Z","user_id":1,"page_id":50}
```

This rule redacted certain strings within the `action` key by replacing any instances
of `purchase` with a string of asterisks. However, other strings within the value
of `action` were unaffected.