AWS Compute Blog

AWS Nitro System gets independent affirmation of its confidential compute capabilities

Anthony Liguori is an AWS VP and Distinguished Engineer for EC2.

Customers around the world trust AWS to keep their data safe, and keeping their workloads secure and confidential is foundational to how we operate. Since the inception of AWS, we have relentlessly innovated on security, privacy tools, and practices to meet, and even exceed, our customers’ expectations.

The AWS Nitro System is the underlying platform for all modern AWS compute instances which has allowed us to deliver the data isolation, performance, cost, and pace of innovation that our customers require. It’s a pioneering design of specialized hardware and software that protects customer code and data from unauthorized access during processing.

When we launched the Nitro System in 2017, we delivered a unique architecture that restricts any operator access to customer data. This means no person, or even service, from AWS can access data when it is being used in an Amazon EC2 instance. We knew that designing the system this way would present several architectural and operational challenges for us. However, we also knew that protecting customers’ data in this way was the best way to support our customer’s needs.

When AWS made its Digital Sovereignty Pledge last year, we committed to providing greater transparency and assurances to customers about how AWS services are designed and operated, especially when it comes to handling customer data. As part of that increased transparency, we engaged NCC Group, a leading cybersecurity consulting firm based in the United Kingdom, to conduct an independent architecture review of the Nitro System and the security assurances we make to our customers. NCC has now issued its report and affirmed our claims.

The report states, “As a matter of design, NCC Group found no gaps in the Nitro System that would compromise [AWS] security claims.” Specifically, the report validates the following statements about our Nitro System production hosts:

  1. There is no mechanism for a cloud service provider employee to log in to the underlying host.
  2. No administrative API can access customer content on the underlying host.
  3. There is no mechanism for a cloud service provider employee to access customer content stored on instance storage and encrypted EBS volumes.
  4. There is no mechanism for a cloud service provider employee to access encrypted data transmitted over the network.
  5. Access to administrative APIs always requires authentication and authorization.
  6. Access to administrative APIs is always logged.
  7. Hosts can only run tested and signed software that is deployed by an authenticated and authorized deployment service. No cloud service provider employee can deploy code directly onto hosts.

The report details NCC’s analysis for each of these claims. You can also find additional details about the scope, methodology, and steps that NCC used to evaluate the claims.

How Nitro System protects customer data

At AWS, we know that our customers, especially those who have sensitive or confidential data, may have worries about putting that data in the cloud. That’s why we’ve architected the Nitro System to ensure that your confidential information is as secure as possible. We do this in several ways:

There is no mechanism for any system or person to log in to Amazon EC2 servers, read the memory of EC2 instances, or access any data on encrypted Amazon Elastic Block Store (EBS) volumes.

If any AWS operator, including those with the highest privileges, needs to perform maintenance work on the EC2 server, they can do so only by using a strictly limited set of authenticated, authorized, and audited administrative APIs. Critically, none of these APIs have the ability to access customer data on the EC2 server. These restrictions are built into the Nitro System itself, and no AWS operator can circumvent these controls and protections.

The Nitro System also protects customers from AWS system software through the innovative design of our lightweight Nitro Hypervisor, which manages memory and CPU allocation. Typical commercial hypervisors provide administrators with full access to the system, but with the Nitro System, the only interface operators can use is a restricted API. This means that customers and operators cannot interact with the system in unapproved ways and there is no equivalent of a “root” user. This approach enhances security and allows AWS to update systems in the background, fix system bugs, monitor performance, and even perform upgrades without impacting customer operations or customer data. Customers are unaffected during system upgrades, and their data remains protected.

Finally, the Nitro System can also provide customers an extra layer of data isolation from their own operators and software. AWS created AWS Nitro Enclaves, which allow for isolated compute environments, which is ideal for organizations that need to process personally identifiable information, as well as healthcare, financial, and intellectual property data within their compute instances. These enclaves do not share memory or CPU cores with the customer instance. Further, Nitro Enclaves have cryptographic attestation capabilities that let customers verify that all of the software deployed has been validated and not compromised.

All of these prongs of the Nitro System’s security and confidential compute capabilities required AWS to invest time and resources into building the system’s architecture. We did so because we wanted to ensure that our customers felt confident entrusting us with their most sensitive and confidential data, and we have worked to continue earning that trust. We are not done and this is just one step AWS is taking to increase the transparency about how our services are designed and operated. We will continue to innovate on and deliver unique features that further enhance our customers’ security without compromising on performance.

Learn more:

Watch Anthony speak about AWS Nitro System Security here.