An integrated circuit for data encryption/decryption and secure key management is disclosed. The integrated circuit may be used in conjunction with other integrated circuits, processors, and software to construct a wide variety of secure data processing, storage, and communication systems. A preferred embodiment of the integrated circuit includes a symmetric block cipher that may be scaled to strike a favorable balance among processing throughput and power consumption. The modular architecture also supports multiple encryption modes and key management functions such as one-way cryptographic hash and random number generator functions that leverage the scalable symmetric block cipher. The integrated circuit may also include a key management processor that can be programmed to support a wide variety of asymmetric key cryptography functions for secure key exchange with remote key storage devices and enterprise key management servers. Internal data and key buffers enable the device to re-key encrypted data without exposing data. The key management functions allow the device to function as a cryptographic domain bridge in a federated security architecture.