An HSM management hub coordinates the distribution and synchronization of cryptographic material across a fleet of connected hardware security modules (“HSMs”). Cryptographic material is exchanged between HSMs in the fleet in a cryptographically protected format. In some examples, the cryptographic material is encrypted using a common fleet key maintained by the HSMs in the fleet. In other examples, the cryptographic material is protected using asymmetric cryptographic keys that are associated with the members of the HSM fleet. The HSM management hub may be used to divide the HSM fleet into subdomains by providing domain keys to subsets of HSMs within the HSM fleet. Cryptographic information that is encrypted with particular domain keys can be distributed across the entire HSM fleet, and restricted to use by authorized HSMs that are in possession of the particular domain keys.