The value proposition of an HSM is that sensitive key material never leaves the hardware in plaintext (or at all, in the case of the SafeNet HSMs used by Amazon). An attacker who compromises a machine with access to the HSM is therefore able to perform whatever operations that machine is authorized to perform, but nothing more. Crucially, they cannot steal the key material and then go off and use it elsewhere. They have to stay connected to the machine that has the access they need. Protecting against offline attacks is a pretty big gain.<p>&gt; Amazon says they don&#x27;t have access to your HSM but presumably they do if they wanted to.<p>I wouldn&#x27;t be so sure. As far as I can tell, once you&#x27;ve provisioned an HSM from Amazon you have full administrator access. That includes control over all trusted SSH certs, users, etc. Of course Amazon has physical access, but that doesn&#x27;t give them access to the HSM&#x27;s crypto functions or the key material.