Before you can send requests for CyberSource REST API services that are authenticated using HTTP Signature, you must create a shared secret key for your CyberSource merchant account in the Business Center.
HTTP Signature authentication is provided by a Base-64 encoded transaction key, represented in a string format.
To create a shared secret key certificate:
  1. Log in to the Business Center.
    Production Environment: businesscenter.cybersource.com
  2. On the left navigation panel, click the
    Payment Configuration
     icon.
  3. Click
    Key Management
    .
    The Key Management page appears.
  4. Click
    Generate Key
    .
    The Create Key page appears.
  5. Select
    REST Shared Secret
    .
  6. Copy the generated key to your clipboard by clicking the clipboard icon, or click
    Download key
     to download the shared secret.
Now you are ready to generate the header.