Systems and methods that support secure code downloading are provided. In one embodiment, a method that securely downloads code may include, for example, one or more of the following: receiving a command in a security processor; loading an encryption or decryption key based on the received command; configuring the security processor with a selected scrambling type and a selected signature type based on the received command; and processing incoming code using the loaded encryption or decryption key and the configured security processor.