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In the history of access control, nearly every system designed has relied on the operating system (OS) to enforce the access control protocols. However, if the OS (and specifically root access) is compromised, there are few if any solutions that can get users back into their system efficiently. In this work, we have proposed a novel approach that allows secure and efficient rollback of file access control after an adversary compromises the OS and corrupts the access control metadata. Our key observation is that the underlying flash memory typically performs out-of-place updates. Taking advantage of this unique feature, we can extract the “stale data” specific for OS access control, by performing low-level disk forensics over the raw flash memory. This allows efficiently rolling back the OS access control to a state pre-dating the compromise. To justify the feasibility of the proposed approach, we have implemented it in a computing device using file system EXT2/EXT3 and open-sourced flash memory firmware OpenNFM. We also evaluated the potential impact of our design on the original system. Experimental results indicate that the performance of the affected drive is not significantly impacted.
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A Generalized Model for Modern Hierarchical Memory System
Memory system is critical to architecture design which can significantly impact application performance. Concurrent Average Memory Access Time (C-AMAT) is a model for analyzing and optimizing memory system performance using a recursive definition of the memory access latency along the memory hierarchy. The original C-AMAT model, however, does not provide the necessary granularity and flexibility for handling modern memory architectures with heterogeneous memory technologies and diverse system topology. We propose to augment C-AMAT to take into consideration the idiosyncrasies of individual cache/memory components as well as their topological arrangement in the memory architecture design. Through trace-based simulation, we validate the augmented model and examine the memory system performance with insight unavailable using the original C-AMAT model.
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- PAR ID:
- 10423827
- Date Published:
- Journal Name:
- 2022 Winter Simulation Conference (WSC)
- Page Range / eLocation ID:
- 2178 to 2188
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/WSC57314.2022.10015298
