Which information is readable to Cisco Collaboration Software in the cloud?

No information is readable to Cisco Collaboration Software in the cloud. Cisco Collaboration Software uses end-to-end encryption to protect the data and privacy of its users. End-to-end encryption means that the data is encrypted at the source device and decrypted only at the destination device. No one, including Cisco, can access or read the data while it is in transit or at rest in the cloud. Cisco Collaboration Software uses strong encryption algorithms and keys that are generated and managed by the users themselves12

References: 1: Cisco Collaboration Security - Cisco 1 2: Cisco Webex Security White Paper - Cisco 2