Approaches for configuring a programmable integrated circuit (IC) are disclosed. Encrypted configuration data is input to the programmable IC, and the encrypted configuration data is stored in configuration memory of the programmable IC. As the encrypted configuration data is input, a determination is made as to whether or not the encrypted configuration data is authentic. In response to the encrypted configuration data being authentic, the encrypted configuration data is read from the configuration memory and decrypted, and the decrypted configuration data is stored back in the configuration memory.