  Cloud computing has emerged as a corner stone of today's computing landscape.
More and more customers who outsource their infrastructure benefit from the
manageability, scalability and cost saving that come with cloud computing.
Those benefits get amplified by the trend towards microservices. Instead of
renting and maintaining full VMs, customers increasingly leverage container
technologies, which come with a much more lightweight resource footprint while
also removing the need to emulate complete systems and their devices.
  However, privacy concerns hamper many customers from moving to the cloud and
leveraging its benefits. Furthermore, regulatory requirements prevent the
adaption of cloud computing in many industries, such as health care or finance.
Standard software isolation mechanisms have been proven to be insufficient if
the host system is not fully trusted, e.g., when the cloud infrastructure gets
compromised by malicious third-party actors. Consequently, confidential
computing is gaining increasing relevance in the cloud computing field.
  We present Trusted Container Extensions (TCX), a novel container security
architecture, which combines the manageability and agility of standard
containers with the strong protection guarantees of hardware-enforced Trusted
Execution Environments (TEEs) to enable confidential computing for container
workloads. TCX provides significant performance advantages compared to existing
approaches while protecting container workloads and the data processed by them.
Our implementation, based on AMD Secure Encrypted Virtualization (SEV), ensures
integrity and confidentiality of data and services during deployment, and
allows secure interaction between protected containers as well as to external
entities. Our evaluation shows that our implementation induces a low
performance overhead of 5.77% on the standard SPEC2017 benchmark suite.
