Controlled use of a hardware security module

Disclosed is a method of using a hardware security module 10 that can be connected to computer systems 212, 213. The computer systems being connectable to a server 12 within a common network 14. The hardware security module has a volatile memory 20, and a persistent or non-volatile memory 22, with a network address 18 of the server, an encrypted secret entity 32 and a private key 30. The server has a wrapping key 24 and a public key 26. When the hardware security module is connected to one of the computer systems, a secure connection 16 is established between the module and the server, the wrapping key is then retrieved, via the secure connection, from the server and stored in the volatile memory of the module. The key is then used to decrypt the encrypted secret entity and the decrypted secret entity 28 is stored in the volatile memory of the module. Also disclosed is a method of initialising a server and a connected hardware security module by encrypting and storing the secret entity in the persistent memory of the module.