Side channel protection imposes substantial area, performance, and/or energy overhead, rendering such hardware unsuitable for devices that have space or battery constraints, e.g., head-mounted display (HMD) devices. To safeguard user data in such devices, energy efficient encryption techniques are necessary. This disclosure describes an in-line encryption engine that uses selective masking. The first and last rounds of encryption are accorded maximum protection by incorporating all masking features, while intermediate rounds are only partially masked at steps that are determined as likely vulnerable, or are left unmasked. Selective round masking in this manner provides data protection with low cost, and is suitable for use in devices with space or battery constraints, such as HMD devices.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.