A secure cloud computing platform. The platform has a pool of secure computing devices such that each can be allocated to a customer as with other computing resources. Each secure computing device may be configured by a customer with a key and software for performing operations on sensitive data. The customer may submit data, defining a job for execution on the platform, as cyphertext. The secure computing device may perform operations on that data, which may include decrypting the data with the key and then executing the software to perform an operation on cleartext data. This operation, and the data on which it is performed, though in cleartext, may be inaccessible to the operator of the cloud computing platform. The device may operate according to a secure protocol under which the software is validated before loading and the device is provisioned with a key shared with the customer.