AMD SEV-SNP: memory encryption, integrity, and the SEV progression

SEV, SEV-ES, and SEV-SNP compared

The Reverse Map Table and page-validation protocol let SNP track which guest owns a page and whether that page is in an expected state. The design aims to block software replay, corruption, aliasing, and remapping attacks by a malicious hypervisor.SNP

Runtime attestation and VCEK

A guest can request an SNP attestation report at runtime and place application-controlled data into the request for endpoint binding. The report is signed through AMD’s Versioned Chip Endorsement Key model, which binds a key to a particular chip and reported trusted computing base version. Verification still needs freshness, expected measurement, policy and version checks; a valid VCEK signature is not a universal approval.VCEK,SNP

• Validate the AMD certificate chain and VCEK for the reported chip/TCB.
• Enforce a fresh challenge and application/session binding.
• Compare the launch measurement and policy with approved values.
• Check TCB versions and security advisories; reject downgrades below policy.
• Release secrets only after the relying party accepts the verifier result.

What SEV-SNP does not protect

• Denial of service by the host or infrastructure operator.
• Shared pages, device input, and other deliberately untrusted I/O paths.
• Vulnerabilities, malware, or unsafe behavior inside the guest.
• Every cache, page-fault, performance, fingerprinting, or ciphertext side channel.
• Online DRAM-bus integrity attacks in the base SNP threat model.
• Ciphertext hiding across every EPYC generation; AMD identifies it as a newer platform feature and publishes generation-specific guidance.

Customer fit and deployment questions

SEV-SNP is a strong fit for lift-and-shift confidential VMs, cloud services that need a malicious-hypervisor threat model, and AMD-hosted confidential GPU systems. It preserves a conventional guest environment, so the guest kernel and application stack remain trusted. Device assignment, migration, debugging, observability, firmware, and cloud availability vary by platform.