Behind the last line of defense: Surviving SoC faults and intrusions; Volp, Marcus ; in Computers & Security (2022), 123 Today, leveraging the enormous modular power, diversity and flexibility of manycore systems-on-a-chip (SoCs) requires careful orchestration of complex and heterogeneous resources, a task left to low-level ... [more ▼] Today, leveraging the enormous modular power, diversity and flexibility of manycore systems-on-a-chip (SoCs) requires careful orchestration of complex and heterogeneous resources, a task left to low-level software, e.g., hypervisors. In current architectures, this software forms a single point of failure and worthwhile target for attacks: once compromised, adversaries can gain access to all information and full control over the platform and the environment it controls. This article proposes Midir, an enhanced manycore architecture, effecting a paradigm shift from SoCs to distributed SoCs. Midir changes the way platform resources are controlled, by retrofitting tile-based fault containment through well known mechanisms, while securing low-overhead quorum-based consensus on all critical operations, in particular privilege management and, thus, management of containment domains. Allowing versatile redundancy management, Midir promotes resilience for all software levels, including at low level. We explain this architecture, its associated algorithms and hardware mechanisms and show, for the example of a Byzantine fault tolerant microhypervisor, that it outperforms the highly efficient MinBFT by one order of magnitude. [less ▲] Detailed reference viewed: 336 (7 UL) Threat Adaptive Byzantine Fault Tolerant State-Machine ReplicationSimoes Silva, Douglas ; Graczyk, Rafal ; et alScientific Conference (2021, September) Critical infrastructures have to withstand advanced and persistent threats, which can be addressed using Byzantine fault tolerant state-machine replication (BFT-SMR). In practice, unattended cyberdefense ... [more ▼] Critical infrastructures have to withstand advanced and persistent threats, which can be addressed using Byzantine fault tolerant state-machine replication (BFT-SMR). In practice, unattended cyberdefense systems rely on threat level detectors that synchronously inform them of changing threat levels. How- ever, to have a BFT-SMR protocol operate unattended, the state- of-the-art is still to configure them to withstand the highest possible number of faulty replicas f they might encounter, which limits their performance, or to make the strong assumption that a trusted external reconfiguration service is available, which introduces a single point of failure. In this work, we present ThreatAdaptive the first BFT-SMR protocol that is automatically strengthened or optimized by its replicas in reaction to threat level changes. We first determine under which conditions replicas can safely reconfigure a BFT-SMR system, i.e., adapt the number of replicas n and the fault threshold f, so as to outpace an adversary. Since replicas typically communicate with each other using an asynchronous network they cannot rely on consensus to decide how the system should be reconfigured. ThreatAdaptive avoids this pitfall by proactively preparing the reconfiguration that may be triggered by an increasing threat when it optimizes its performance. Our evaluation shows that ThreatAdaptive can meet the latency and throughput of BFT baselines configured statically for a particular level of threat, and adapt 30% faster than previous methods, which make stronger assumptions to provide safety. [less ▲] Detailed reference viewed: 360 (41 UL) Characterizing the Impact of Network Delay on Bitcoin MiningCao, Tong ; Decouchant, Jérémie ; et alScientific Conference (2021, September) Detailed reference viewed: 235 (40 UL) |
||