Secure communications between services or components of a cloud computing system, are facilitated by generating at a first service provided by a first computing entity of a cloud computing system, a request for computing resources, generating at the first computing entity a digital data signature based at least on the request, using a private key associated with the first service; and inserting the digital data signature within an HTTP header associated with the request. A computer data network is used to communicate the request to a second service. The second service extracts the digital data signature and uses a public key to validate the digital data signature.