I&#x27;m relying on <a href="https:&#x2F;&#x2F;d0.awsstatic.com&#x2F;whitepapers&#x2F;KMS-Cryptographic-Details.pdf" rel="nofollow">https:&#x2F;&#x2F;d0.awsstatic.com&#x2F;whitepapers&#x2F;KMS-Cryptographic-Detai...</a>. There are HSMs, I guess, but they&#x27;r only used to back up the keys when they&#x27;re stored offline for durable backups. I hadn&#x27;t seen the claim on the main page, but I&#x27;d consider it to be misleading, presuming that the cryptographic details whitepaper didn&#x27;t totally misstate the design.