A security module securely manages keys. The security module is usable to implement a cryptography service that includes a request processing component. The request processing component responds to requests by causing the security module to perform cryptographic operations that the request processing component cannot perform due to a lack of access to appropriate keys. The security module may be a member of a group of security modules that securely manage keys. Techniques for passing secret information from one security module to the other prevent unauthorized access to secret information.