[Cryptography] HSM's to be required for Code Signing Certificates

[Ron Garret]

On Jan 27, 2017, at 12:52 AM, Peter Gutmann <pgut001 at cs.auckland.ac.nz> wrote:

> Natanael <natanael.l at gmail.com> writes:
> 
>> Program the HSM to only accept customer requests that are signed by their
>> trusted keys, or sent over a trusted channel directly to the HSM. Any
>> overrides by the cloud company MUST be logged and audited by an independent
>> entity (such as if the customer reports they lost the authentication key).
> 
> That's not how HSM's work though.  The interface to an HSM, at least for
> signing purposes, is "perform a private-key operation on this short byte
> string" (a.k.a. "sign this hash").  That's it.  Using an HSM merely moves the
> key from a potentially attacker-controlled PC to an external crypto box that
> does anything the attacker-controlled PC wants.  It's perfect for auditing
> compliance because you can point to a physical artefact that contains the key,
> but only offers a marginal increase in actual security.

Unless the HSM has its own I/O, like this one:

https://sc4.us/hsm

When asked to sign, the SC4-HSM displays the hash to be signed on the built-in display and waits for the user to confirm by pressing a button on the HSM.

(Disclosure: this is my product.)

rg