I'd like to address the difference between a SmartCard and an HSM as I feel like the author doesn't acknowledge some of the practical differences. While at the core they are both "hardware security", i.e. a physical chip that implements security, an "HSM" as I have commonly seen the term used is a completely different thing in most other ways.<p>An HSM is typically a 1-2U server, that is designed to provide high throughput of cryptographic operations. It is ultimately a collection of a few high performance servers networked together, with some custom ICs - not just a small chip. As a result, you pay up to tens of thousands of dollars for one, because it's a piece of critical infrastructure that is made to high tolerances. It's akin to buying hardware load balancers or firewalls appliances.<p>In addition to this, the validation process of an HSM is long. An HSM company will likely have teams of hardware engineers, software engineers, and specialised cryptography teams. There are audits for things like FIPS compliance, as well as extensive pentesting by external companies. All of this is expensive, to create a device that will never be mass market.