# Additional credentials
source: https://developer.mastercard.com/identity-insights-for-transactions/tutorial/sandbox-access/step5/index.md

## Additional credentials {#additional-credentials}

Additional credentials are required to facilitate payload encryption. These can be created as part of the create project
flow or added after the project has been created by clicking "Skip this step".  

If you choose to skip this step the project will be created without the certificate needed for payload encryption being
added, requiring you to add this key after the project has been created via the "Sandbox Credentials" page.

To create the credential required for payload encryption as part of the project creation:

1. Click **Create project** and wait for the steps to complete.
2. Click the **Download key file** button and save the zip file containing:
   1. \*-signing.crt file containing the **mTLS certificate**.
   2. \*-private-key.key file containing the **mTLS private key**, which is secured by the Keystore password specified earlier in the flow.
   3. identity-insights-for-transactions-clientenc-\*-client-encryption-key.pem file containing the **client encryption certificate**.
3. Click **Open project**.
4. You will be redirected to the Project Summary Page from where you can access the various keys generated.

Note: To encrypt a JSON payload with the downloaded keys, use a tool (such as Open SSL) to first extract the public key from the CRT file as a PEM file, and then utilise this PEM file within your encryption operation

![](https://static.developer.mastercard.com/content/identity-insights-for-transactions/uploads/additional_credentials.png)
![](https://static.developer.mastercard.com/content/identity-insights-for-transactions/uploads/confirm_and_download_keys.png)
![](https://static.developer.mastercard.com/content/identity-insights-for-transactions/uploads/open_project_sandbox.png)
![](https://static.developer.mastercard.com/content/identity-insights-for-transactions/uploads/project_dashboard_sandbox.png)

**Note**: Please follow the below instructions to convert crt file to pfx file

* Go to Project Summary and Select "Sandbox" under credentials.
* Select the certificate created and click download.

![](https://static.developer.mastercard.com/content/identity-insights-for-transactions/uploads/convert_crt2pfx_format.png)

* Once the certificate is downloaded in the crt format use the below command to convert the crt file to pfx file

openssl pkcs12 -export -out certificate.pfx -inkey keyfile.key -in certificate.crt