uMMU: Securing Data Confidentiality with Unobservable Memory Subsystem

Ensuring data confidentiality in a computing system's memory hierarchy proved to be a formidable challenge with the large attack surface. Diverse and powerful attacks threaten data confidentiality. Memory safety is notoriously hard to achieve with unsafe languages, thereby empowering adversaries with unauthorized memory accesses, as represented by the HeartBleed incident. More recently, microarchitectural side channel attacks reign as a prevalent threat against data confidentiality that affects program execution including the safeguarded ones inside TEEs.