Reducing costs in HSM-based data centers

Hardware Security Modules (HSM) are special devices designed for cryptographic operations and cryptographic keys management. The keys are stored internally to the HSM and never exposed. All the operations involving the keys are performed inside the HSM and only the result is given outside. To store all the keys that have to be managed an HSM must have a lot of storage space. Large data centers that handle millions of cryptographic keys needed to host many HSMs. Related costs are directly proportional to the number of HSMs used: hardware, energy consumption, network hosting, network speed, management. In this paper we present two approaches that allow to save space for storing keys in an HSM, thus reducing the number of needed HSMs and consequently all other related costs. Cost savings comes at the expense of computation time.