Cloud Encryption Gateways (CEG) and Cloud Access Security Brokers(CASB) are becoming popular to ensure the security and confidentiality of the data leaving to Cloud Service Providers. How do they provide such services on the data leaving the organization at the gateway ? Do they do TLSProxy/SSLProxy for the traffic ?
CASBs are on premises or cloud based security policy enforcement points which are placed between consumers of cloud services and cloud service providers.
CASB reside between cloud services and their users and intercepts the sensitive data and replace it with tokens or encrypted values before it is passed to the cloud for processing and storage. CASB can reside on premise as a gateway. For better understanding, see diagrammatic representation.