> For the complete documentation index, see [llms.txt](https://docs.fractalworks.io/joule/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fractalworks.io/joule/use-case-examples/telco/anonymise-imsi.md).

# Anonymise IMSI

In-flight data anonymisation is a key feature for solutions that process sensitive  data. Joule provides this feature through a custom encryption obfuscator.

***

This example performs field level anonymisation on the customer IMSI using RSA encryption. Encryption keys are dynamically generated from a random  initialisation vector with the resulting keys stored in a user defined directory. Encryption processor Documentation can be found [here](/joule/components/processors/transformation/obfuscation/encryption.md).

## Use case configuration

*File: app-anonymisation.env*

```bash
SOURCEFILE=conf/sources/mobileSimulatedStream.yaml
ENGINEFILE=conf/usecases/anonymisation/mobileEventAnonymisation.yaml
PUBLISHFILE=conf/publishers/anonymisedMobileEventFile.yaml
```

## Pipeline configuration <a href="#processor-configuration" id="processor-configuration"></a>

This pipeline will encrypt the event IMSI using sytem generated keys.

```yaml
processing unit:
  pipeline:
    - filter:
          expression: "(imsi !== null ) ? true : false;"
         
    - obfuscation:
        name: imsiEncryption
        fields:
          imsi:
            encryption:
              decrypt: false
              key location: ./keytmp
              aes bit length: 128
              rsa bit length: 2048
              rotate keys: true
```