# SNP

## Glosssary

This section explains abbreviations used in SNP implementation.

### Attestation Key (AK)

### AMD Root Key (ARK)

### AMD Signing Key (ASK)

### Versioned Chip Endorsement Key (VCEK)

For more information see [SNP WhitePaper](https://www.amd.com/system/files/TechDocs/SEV-SNP-strengthening-vm-isolation-with-integrity-protection-and-more.pdf)

### Host (Hardware?) Compatibility Layer (HCL)

No public information. Azure compute API has a field `isHostCompatibilityLayerVm`, with only a [single sentence of documentation](https://learn.microsoft.com/en-us/azure/virtual-machines/windows/instance-metadata-service?tabs=windows).