A company processes highly sensitive customer data (for example, for tokenization) and wants an isolated compute environment carved out of an existing EC2 instance that has no persistent storage, no external network access, and can cryptographically prove to a service like AWS KMS exactly what code it's running before being granted decryption access. Which approach fits?
- A second, network-isolated EC2 instance placed in a private subnet with no internet gateway route
- An EC2 instance running inside a Dedicated Host, since dedicated tenancy alone guarantees this level of isolation
- An Auto Scaling group configured with a warm pool, since pooled instances have no active network path until put into service
- An AWS Nitro Enclave: an isolated virtual machine carved out of CPU and memory from a Nitro-based parent EC2 instance, with no persistent storage and no external network connectivity of its own (communicating with the parent only over a local vsock channel), which can generate a Nitro Hypervisor-signed cryptographic attestation document that AWS KMS can use as a condition for authorizing decryption
Why D? And why not the others?
Correct answer: D. An AWS Nitro Enclave: an isolated virtual machine carved out of CPU and memory from a Nitro-based parent EC2 instance, with no persistent storage and no external network connectivity of its own (communicating with the parent only over a local vsock channel), which can generate a Nitro Hypervisor-signed cryptographic attestation document that AWS KMS can use as a condition for authorizing decryption
A Nitro Enclave is purpose-built for exactly this scenario: it's created by partitioning CPU cores and memory from a Nitro-based parent EC2 instance into an isolated virtual machine that has no persistent storage and no external network connectivity of its own, communicating with its parent instance solely over a local vsock channel, and it can produce a cryptographic attestation document, signed by the Nitro Hypervisor, containing measurements of the enclave's code that an external service such as AWS KMS can evaluate as a condition before authorizing a decryption operation. A second, ordinary EC2 instance in a private subnet with no internet route can restrict inbound and outbound internet access, but it still has persistent EBS storage, a full general-purpose OS a compromised process could tamper with, and no built-in mechanism to cryptographically attest its own code integrity to KMS. Dedicated Host tenancy only changes which physical server underlies an instance for licensing or compliance purposes; it says nothing about that instance's storage persistence, network isolation, or ability to attest its code. An Auto Scaling warm pool's pooled instances are simply stopped EC2 instances waiting to be activated; they still have persistent EBS storage and no attestation capability, and the lack of an active network path is only a temporary side effect of being stopped, not a designed security property.
Source: AWS Nitro Enclaves documentation: Nitro Enclaves concepts — enclave isolation and cryptographic attestation