# Adding Keys and CSR
source: https://developer.mastercard.com/authentication-facilitator/documentation/tutorials-and-guides/addkey/index.md

1. Login to Mastercard Developers.
2. Select your existing project.
3. Select the Production Credentials option from the left navigation bar.
4. Select **Add Key**

## Add Mastercard Encryption Key {#add-mastercard-encryption-key}

1. Select **Mastercard Encryption Key** from the list, this key is used to decrypt the sensitive data encrypted by Mastercard in the payload sent by Mastercard. ![KEY Type Selection](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/key_selection_MA_Key.png)

#### Option 1: Use your existing private key {#option-1-use-your-existing-private-key}

1. If you want to use your existing private key (generated and managed by you), then select option **Use an existing private key** or **Paste in a CSR file** . ![Use Existing Key](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/existing_private_key.png)
2. Provide the key alias, upload or paste the CSR file, and select Create Key.
3. After the certificate is signed and stored, you will be redirected to the project credentials page, where you can see that the Mastercard Encryption Key has been added. ![Key Success](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/MA_Key_Success.png)

#### Option 2: Generate a new private key {#option-2-generate-a-new-private-key}

1. Please select **Generate a new private key** option.
2. Provide **Key alias** and **Keystore password** and click **Proceed** . ![Generate New Key](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/RequestProdAccess_MTF_ProjectCredentials.png)
3. The key creation process starts and completes within a few seconds.
4. Download key information by clicking **Download Key File** . ![Download Keys](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/MA_Key_Download.png)
5. After successfully downloading the key file, the following key information will be available:
   1. P12 file for Mastercard encryption key - Issuer will use this to decrypt encrypted (encrypted by Mastercard) data that receives in the request.
6. By selecting **Open Project** , you will be redirected to the project credential page; where you can see Mastercard Encryption Key has been added.  
   ![Key Success](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/MA_Key_Success.png)

Please map the key fingerprint with private key, so you can use correct key to decrypt sensitive data from the request.

## Add Client Encryption Key {#add-client-encryption-key}

Please add Client Encryption Key if you decide to provide sensitive data in the response that is required to be encrypted as per the specification.

1. Select **Client Encryption Key** from the list. This key is used to decrypt sensitive data from the request. ![KEY Type Selection](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/select_client_encKey.png)
2. Select **Create Key** . ![Create Key](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/create_client_encKey.png)
3. Key Creation process starts and completes in few seconds.
4. Download key information by clicking **Download Key File** . ![Download Keys](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/save_client_EncKey.png)
5. By selecting **Open Project** , will be redirected to project credential page; where you can see Client Encryption Key has been added.  
   ![Key Success](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/tutorials-and-guides/images/view_clinet_encKey.png)

Please share the fingerprint as part of encryption payload so Mastercard can identify corresponding key and is able to decrypt the sensitive data from the response.