Towards (Really) Safe and Fast Confidential I/O

Confidential cloud computing enables cloud tenants to distrust their service provider. Achieving confidential computing solutions that provide concrete security guarantees requires not only strong mechanisms, but also carefully designed software interfaces. In this paper, we make the observation that confidential I/O interfaces, caught in the tug-of-war between performance and security, fail to address both at a time when confronted to interface vulnerabilities and observability by the untrusted host. We discuss the problem of safe I/O interfaces in confidential computing, its implications and challenges, and devise research paths to achieve confidential I/O interfaces that are both safe and fast.