I am a computer architect with broad interests in adjacent areas. Recently, a lot of my work has been related to security (from applied cryptography to hardware-based attacks and defenses) and domain-specific acceleration (from algorithm to hardware design). Here is my
CV and
Google Scholar.
Augury: Using Data Memory-Dependent Prefetchers to Leak Data at Rest, Oakland/SP 2022 [info page] [paper] [conference talk] CSAW'22 Applied Research Competition Runner-Up (2nd place)
Graphite: Optimizing Graph Neural Networks on CPUs Through Cooperative Software-Hardware Techniques, ISCA 2022 [paper] [conference talk]
Optimizing Selective Protection for CNN Resilience, ISSRE 2021 [paper]
Speculative Privacy Tracking (SPT): Leaking Information From Speculative Execution Without Compromising Privacy, MICRO 2021 [paper] [conference talk]
SumMerge: An Efficient Algorithm and Implementation for Weight Repetition-Aware DNN Inference, ICS 2021 [paper]
Opening Pandora's Box: A Systematic Study of New Ways Microarchitecture Can Leak Private Data, ISCA 2021 [paper] [conference talk] Intel Hardware Security Academic Award 2022 (Honorable Mention)
Leaking Secrets Through Compressed Caches, Top Picks 2021 [paper]
Lord of the Ring(s): Side Channel Attacks on the CPU On-Chip Ring Interconnect Are Practical, Security 2021 [paper, slides, conference talk] Nominee for Pwnie Award -- Most Innovative Research
Data Oblivious ISA Extensions for Side Channel-Resistant and High Performance Computing, NDSS 2019 [paper] [conference talk] [open-source release] Distinguished Paper Finalist, CSAW Applied Research Competition Finalist, IEEE Micro Top Picks 2020
Attack Directories, Not Caches: Side Channel Attacks in a Non-Inclusive World, Oakland/SP 2019 [paper] [conference talk]
Freecursive ORAM: [Nearly] Free Recursion and Integrity Verification for Position-based Oblivious RAM, ASPLOS 2015 [paper]
Suppressing the Oblivious RAM Timing Channel While Making Information Leakage and Program Efficiency Trade-offs, HPCA 2014 [paper]
Path ORAM: An Extremely Simple Oblivious RAM Protocol, CCS 2013 [paper] Best Student Paper Award, Top Picks in Hardware & Embedded Security 2018, Test of Time Award
Generalized External Interaction with Tamper-Resistant Hardware with Bounded Information Leakage, CCSW 2013 [paper]
A Framework to Accelerate Sequential Programs on Homogeneous Multicores, VLSI-SOC 2013 [paper]
Integrity Verification for Path Oblivious-RAM, HPEC 2013 [paper]
Design Space Exploration and Optimization of Path Oblivious RAM in Secure Processors, ISCA 2013 [paper]
Towards an Interpreter for Efficient Encrypted Computation, CCSW 2012 [paper]
A Secure Processor Architecture for Encrypted Computation on Untrusted Programs, STC 2012 [paper]
HORNET: a cycle-level multicore simulator, TCAD 2012 [paper]
A Low-overhead Dynamic Optimization Framework on Multicores (short paper), PACT 2012 [paper]
Exploring Many-core Design Templates for FPGAs and ASICs, IJRC 2012 [paper]
Scalable Accurate Multicore Simulation in the 1000 core era, ISPASS 2011 [paper]
Brief Announcement: Distributed Shared Memory based on Computation Migration (short paper), SPAA 2011 [paper]
Bridging the GPGPU-FPGA Efficiency Gap (short paper), FPGA 2011 [paper]
MARC: A Many-Core Approach to Reconfigurable Computing, ReConFig 2010 [paper]
ParaLearn: A Massively Parallel, Scalable System for Learning Interaction Networks on FPGAs, ICS 2010 [paper] [slides] Best Student Paper Award
Papers
GoFetch: Breaking Constant-Time Cryptographic Implementations Using Data Memory-Dependent Prefetchers
Boru Chen, Yingchen Wang, Pradyumna Shome, Christopher W. Fletcher, David Kohlbrenner, Riccardo Paccagnella, Daniel Genkin Appears in the Proceedings of the USENIX Security Symposium (Security), 2024 [info page]
ConjunCT: Learning Inductive Invariants to Prove Unbounded Instruction Safety Against Microarchitectural Timing Attacks
Sushant Dinesh, Madhusudan Parthasarathy, Christopher W. Fletcher To appear in the Proceedings of the IEEE Symposium on Security and Privacy (Oakland/SP), 2024
GPU.zip: On the Side-Channel Implications of Hardware-Based Graphical Data Compression
Yingchen Wang, Riccardo Paccagnella, Zhao Gang, Willy R. Vasquez, David Kohlbrenner, Hovav Shacham, Christopher W. Fletcher Appears in the Proceedings of the IEEE Symposium on Security and Privacy (Oakland/SP), 2024 [info page]
Last-Level Cache Side-Channel Attacks Are Feasible in the Modern Public Cloud
Zirui Zhao, Adam Morrison, Christopher W. Fletcher, Josep Torrellas To appear in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2024
Everywhere All at Once: Co-Location Attacks on Public Cloud FaaS
Zirui Zhao, Adam Morrison, Christopher W. Fletcher, Josep Torrellas To appear in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2024
Secure-by-Construction Design Methodology for CPUs: Implementing Secure Speculation on the RTL
Tobias Jauch, Alex Wezel, Mohammad R. Fadiheh, Philipp Schmitz, Sayak Ray, Jason M. Fung, Christopher W. Fletcher, Dominik Stoffel, Wolfgang Kunz To appear in the Proceedings of the IEEE/ACM 2022 International Conference on Computer-Aided Design (ICCAD), 2023
TeAAL: A Declarative Framework for Modeling Sparse Tensor Accelerators
Nandeeka Nayak, Toluwanimi Odemuyiwa, Shubham Ugare, Christopher W. Fletcher, Michael Pellauer, Joel Emer Appears in the Proceedings of the ACM/IEEE International Symposium on Microarchitecture (MICRO), 2023 IEEE Micro Top Picks 2023 Honorable Mention [paper]
Declassiflow: A Static Analysis for Modeling Non-Speculative Knowledge to Relax Speculative Execution Security Measures
Rutvik Choudhary, Alan Wang, Zirui Zhao, Adam Morrison, Christopher W. Fletcher Appears in the Proceedings of the ACM Conference on Computer and Communications Security (CCS), 2023 [paper]
Synchronization Storage Channels (S2C): Timer-less Cache Side-Channel Attacks on the Apple M1 via Hardware Synchronization Instructions
Jiyong Yu, Aishani Dutta, Trent Jaeger, David Kohlbrenner, Christopher W. Fletcher Appears in the Proceedings of the USENIX Security Symposium (Security), 2023 [paper, slides, conference talk]
DVFS Frequently Leaks Secrets: Hertzbleed Attacks Beyond SIKE, Cryptography, and CPU-Only Data
Yinchen Wang, Riccardo Paccagnella, Alan Wandke, Zhao Gang, Grant Garrett-Grossman, Christopher W. Fletcher, David Kohlbrenner, Hovav Shacham Appears in the Proceedings of the IEEE Symposium on Security and Privacy (Oakland/SP), 2023 [info page] [paper]
All your PC are belong to us: Exploiting Non-control-transfer Instruction BTB Updates for Dynamic PC Extraction
Jiyong Yu, Trent Jaeger, Christopher W. Fletcher Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2023 [paper]
Hertzbleed: Turning Power Side-Channel Attacks Into Remote Timing Attacks on x86
Yinchen Wang, Riccardo Paccagnella, Elizabeth He, Hovav Shacham, Christopher W. Fletcher, David Kohlbrenner (Y. Wang and R. Paccagnella shared lead author) Appears in the IEEE MICRO Top Picks Special Issue (Top Picks), 2023 [paper]
Accelerating Sparse Data Orchestration via Dynamic Reflexive Tiling
Toluwanimi Odemuyiwa, Hadi Asghari-Moghaddam, Michael Pellauer, Kartik Hegde, Po-An Tsai, Neal Crago, Aamer Jaleel, John Owens, Edgar Solomonik, Joel Emer, Christopher W. Fletcher Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2023 [paper] [conference talk]
Untangle: A Principled Framework to Design Low-Leakage, High-Performance Dynamic Partitioning Schemes
Zirui Zhao, Adam Morrison, Christopher W. Fletcher, Josep Torrellas Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2023 IEEE Micro Top Picks 2023 Honorable Mention [paper] [conference talk]
Pagoda: Towards Binary Code Privacy Protection with SGX-based Execute-Only Memory
Jiyong Yu, Xinyang Ge, Trent Jaeger, Christopher W. Fletcher, Weidong Cui Appears in the Proceedings of the IEEE International Symposium on Secure and Private Execution Environment Design (SEED), 2022 [paper]
Hertzbleed: Turning Power Side-Channel Attacks Into Remote Timing Attacks on x86
Yinchen Wang, Riccardo Paccagnella, Elizabeth He, Hovav Shacham, Christopher W. Fletcher, David Kohlbrenner (Y. Wang and R. Paccagnella shared lead author) Appears in the Proceedings of the USENIX Security Symposium (Security), 2022 Pwnie Award -- Best Cryptographic Attack IEEE Micro Top Picks 2022 Intel Bug Bounty [info page] [paper, conference talk]
Binoculars: Contention-Based Side-Channel Attacks Exploiting the Page Walker
Zirui Zhao, Adam Morrison, Christopher W. Fletcher, Josep Torrellas Appears in the Proceedings of the USENIX Security Symposium (Security), 2022 [paper, slides, conference talk]
Augury: Using Data Memory-Dependent Prefetchers to Leak Data at Rest
Jose Rodrigo Sanchez Vicarte, Michael Flanders, Riccardo Paccagnella, Grant Garrett-Grossman, Adam Morrison, Christopher W. Fletcher, David Kohlbrenner (J. Vicarte and M. Flanders shared lead author) Appears in the Proceedings of the IEEE Symposium on Security and Privacy (Oakland/SP), 2022 CSAW'22 Applied Research Competition Runner-Up (2nd place) [info page] [paper] [conference talk]
Graphite: Optimizing Graph Neural Networks on CPUs Through Cooperative Software-Hardware Techniques
Zhangxiaowen Gong; Houxiang Ji, Yao Yao, Christopher W. Fletcher; Christopher J. Hughes; Josep Torrellas Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2022 [paper] [conference talk]
SynthCT: Towards Portable Constant-Time Code
Sushant Dinesh, Grant Garrett-Grossman, Christopher W. Fletcher Appears in the Proceedings of the Internet Society Network and Distributed System Security Symposium (NDSS), 2022 [paper, conference talk]
Optimizing Selective Protection for CNN Resilience
Abdulrahman Mahmoud, Siva Kumar Sastry Hari, Christopher W. Fletcher, Sarita V. Adve, Charbel Sakr, Naresh Shanbhag, Pavlo Molchanov, Michael B. Sullivan, Timothy Tsai, Stephen W. Keckler Appears in the Proceedings of the International Symposium on Software Reliability Engineering (ISSRE), 2021 [paper]
Speculative Privacy Tracking (SPT): Leaking Information From Speculative Execution Without Compromising Privacy
Rutvik Choudhary, Jiyong Yu, Christopher W. Fletcher, Adam Morrison Appears in the Proceedings of the ACM/IEEE International Symposium on Microarchitecture (MICRO), 2021 [paper] [conference talk]
SumMerge: An Efficient Algorithm and Implementation for Weight Repetition-Aware DNN Inference
Rohan Prabhakar, Sachit Kuhar, Rohit Agrawal, Christopher Hughes, Christopher W. Fletcher Appears in the Proceedings of the International Conference on Supercomputing (ICS), 2021 [paper]
Opening Pandora's Box: A Systematic Study of New Ways Microarchitecture Can Leak Private Data
Jose Rodrigo Sanchez Vicarte, Pradyumna Shome, Nandeeka Nayak, Caroline Trippel, Adam Morrison, David Kohlbrenner, Christopher W. Fletcher Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2021 Intel Hardware Security Academic Award 2022 (Honorable Mention) [paper] [conference talk]
Leaking Secrets Through Compressed Caches
Po-An Tsai, Andres Sanchez, Christopher W. Fletcher, Daniel Sanchez Appears in the IEEE MICRO Top Picks Special Issue (Top Picks), 2021 [paper]
Lord of the Ring(s): Side Channel Attacks on the CPU On-Chip Ring Interconnect Are Practical
Riccardo Paccagnella, Licheng Luo, Christopher W. Fletcher Appears in the Proceedings of the USENIX Security Symposium (Security), 2021 Nominee for Pwnie Award -- Most Innovative Research [paper, slides, conference talk]
Double-Cross Attacks: Subverting Active Learning Systems
Jose Rodrigo Sanchez Vicarte, Gang Wang, Christopher W. Fletcher Appears in the Proceedings of the USENIX Security Symposium (Security), 2021 [paper, slides, conference talk]
Speculative Interference Attacks: Breaking Invisible Speculation Schemes
Mohammad Behnia, Prateek Sahu, Riccardo Paccagnella, Jiyong Yu, Zirui Zhao, Xiang Zou, Thomas Unterluggauer, Josep Torrellas, Carlos Rozas, Adam Morrison, Frank Mckeen, Fangfei Liu, Ron Gabor, Christopher W. Fletcher, Abhishek Basak, Alaa Alameldeen Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2021 [paper]
Jamais Vu: Thwarting Microarchitectural Replay Attacks
Dimitrios Skarlatos, Zirui Zhao, Riccardo Paccagnella, Christopher W. Fletcher, Josep Torrellas Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2021 [paper] [slides]
Streamline: A Fast, Flushless Cache Covert-Channel Attack by Enabling Asynchronous Collusion
Gururaj Saileshwar, Christopher W. Fletcher, Moinuddin Qureshi Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2021 [paper] [conference talk]
Mind Mappings: Enabling Efficient Algorithm-Accelerator Mapping Space Search
Kartik Hegde, Po-An Tsai, Sitao Huang, Vikas Chandra, Angshuman Parashar, Christopher W. Fletcher Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2021 [paper] [lightning talk]
Speculative Taint Tracking (STT): A Comprehensive Protection for Speculatively-Accessed Data
Jiyong Yu, Mengjia Yan, Artem Khyzha, Adam Morrison, Josep Torrellas, Christopher W. Fletcher Appears in the Communications of the ACM (CACM), 2021 [paper]
CoTracer and RokWall: Privacy Preserving University Health Apps for COVID-19
Vikram Sharma Mailthody, Amit Agarwal, Nicholas Chen, Andrew Miller, Sanjay Patel, Edward Richter, Christopher W. Fletcher, Mohammad Behnia, Ruihao Yao, Qihao Wang, Jinjun Xiong, Lijian Wang, Leihao Chen, James Wei, Vedant Agarwal, Churan He Appears in the Proceedings of the CoronaDef Workshop (NDSS-CoronaDef), 2021 [paper]
DOVE: A Data-Oblivious Virtual Environment
Hyun Bin Lee, Tushar Jois, Christopher W. Fletcher, Carl A. Gunter Appears in the Proceedings of the Internet Society Network and Distributed System Security Symposium (NDSS), 2021 [paper] [conference talk]
SparseTrain: Leveraging Dynamic Sparsity in Software for Training DNNs on General-Purpose SIMD Processors
Zhangxiaowen Gong, Houxiang Ji, Christopher W. Fletcher, Christopher J. Hughes, Josep Torrellas Appears in the Proceedings of the International Conference on Parallel Architectures and Compilation Techniques (PACT), 2020 [paper]
SAVE: Sparsity-Aware Vector Engine for Accelerating DNN Training and Inference on CPUs
Zhangxiaowen Gong, Houxiang Ji, Christopher W. Fletcher, Christopher Hughes, Sara Baghsorkhi, Josep Torrellas Appears in the Proceedings of the ACM/IEEE International Symposium on Microarchitecture (MICRO), 2020 [paper] [conference talk]
Speculation Invariance (InvarSpec): Faster Safe Execution Through Program Analysis
Zirui Zhao, Houxiang Ji, Mengjia Yan, Jiyong Yu, Christopher W. Fletcher, Adam Morrison, Darko Marinov, Josep Torrellas Appears in the Proceedings of the ACM/IEEE International Symposium on Microarchitecture (MICRO), 2020 [paper] [conference talk]
PyTorchFI: A Runtime Perturbation Tool for DNNs
Abdulrahman Mahmoud, Neeraj Aggarwal, Alex Nobbe, Jose Rodrigo Sanchez Vicarte, Sarita Adve, Christopher W. Fletcher, Iuri Frosio, Siva Kumar Sastry Hari Appears in the Proceedings of the Dependable and Secure Machine Learning (DSN-DSML), 2020 [paper] [open-source release]
Speculative Data-Oblivious Execution: Mobilizing Safe Prediction For Safe and Efficient Speculative Execution
Jiyong Yu, Namrata Mantri, Josep Torrellas, Adam Morrison, Christopher W. Fletcher Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2020 Intel Hardware Security Academic Award 2021 (First Place) [paper] [open-source release]
Scalable Validation of Binary Lifters
Sandeep Dasgupta, Sushant Dinesh, Deepan Venkatesh, Vikram Adve, Christopher W. Fletcher Appears in the Proceedings of the SIGPLAN Conference on Programming Language Design and Implementation (PLDI), 2020 [paper] [open-source release]
HarDNN: Feature Map Vulnerability Evaluation in CNNs
Abdulrahman Mahmoud, Siva Kumar Sastry Hari, Christopher W. Fletcher, Sarita V. Adve, Charbel Sakr, Naresh Shanbhag, Pavlo Molchanov, Michael B. Sullivan, Timothy Tsai and Stephen W. Keckler Appears in the Proceedings of the Workshop on Secure and Resilient Autonomy (SARA), 2020 [paper]
Custos: Practical Tamper-Evident Auditing of Operating Systems Using Trusted Execution
Riccardo Paccagnella, Pubali Datta, Wajih Hassan, Adam Bates, Christopher W. Fletcher, Andrew Miller, Dave Tian Appears in the Proceedings of the Internet Society Network and Distributed System Security Symposium (NDSS), 2020 [paper, slides, conference talk] [open-source release]
Creating Foundations for Secure Microarchitectures with Data-Oblivious ISA Extensions
Jiyong Yu, Lucas Hsiung, Mohamad El Hajj, Christopher W. Fletcher Appears in the IEEE MICRO Top Picks Special Issue (Top Picks), 2020 [paper]
Speculative Taint Tracking (STT): A Comprehensive Protection for Speculatively Accessed Data
Jiyong Yu, Mengjia Yan, Artem Khyzha, Adam Morrison, Josep Torrellas, Christopher W. Fletcher Appears in the IEEE MICRO Top Picks Special Issue (Top Picks), 2020 [paper]
MicroScope: Enabling Microarchitectural Replay Attacks
Dimitrios Skarlatos, Mengjia Yan, Bhargava Gopireddy, Read Sprabery, Josep Torrellas, Christopher W. Fletcher Appears in the IEEE MICRO Top Picks Special Issue (Top Picks), 2020 [paper]
Game of Threads: Enabling Asynchronous Poisoning Attacks
Jose Rodrigo Sanchez Vicarte, Ben Schreiber, Riccardo Paccagnella, Christopher W. Fletcher Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2020 [paper] [conference talk] [open-source release]
Safecracker: Leaking Secrets through Compressed Caches
Po-An Tsai, Andres Sanchez, Christopher W. Fletcher, Daniel Sanchez Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2020 IEEE Micro Top Picks 2021 [paper] [conference talk] [open-source release]
Cache Telepathy: Leveraging Shared Resource Attacks to Learn DNN Architectures
Mengjia Yan, Christopher W. Fletcher, Josep Torrellas Appears in the Proceedings of the USENIX Security Symposium (Security), 2020 [paper, slides, conference talk]
ExTensor: An Accelerator for Sparse Tensor Algebra
Kartik Hegde, Hadi Asghari-Moghaddam, Michael Pellauer, Neal Crago, Aamer Jaleel, Edgar Solomonik, Joel Emer, Christopher W. Fletcher Appears in the Proceedings of the ACM/IEEE International Symposium on Microarchitecture (MICRO), 2019 IEEE Micro Top Picks 2020 Honorable Mention [paper]
Speculative Taint Tracking (STT): A Comprehensive Protection for Speculatively Accessed Data
Jiyong Yu, Mengjia Yan, Artem Khyzha, Adam Morrison, Josep Torrellas, Christopher W. Fletcher Appears in the Proceedings of the ACM/IEEE International Symposium on Microarchitecture (MICRO), 2019 Best Paper Award IEEE Micro Top Picks 2020 CACM Highlight [paper] [formal analysis] [open-source release]
A Retrospective on Path ORAM
Emil Stefanov, Marten van Dijk, Elaine Shi, Christopher W. Fletcher, Ling Ren, Xiangyao Yu, Srinivas Devadas Appears in the IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems (TCAD), 2019 [paper]
Approximate Checkers
Abdulrahman Mahmoud, Paul Reckamp, Panqiu Tang, Christopher W. Fletcher, Sarita V. Adve Appears in the Proceedings of the Workshop on Approximate Computing Across the Stack (WAX), 2019 [paper]
MicroScope: Enabling Microarchitectural Replay Attacks
Dimitrios Skarlatos, Mengjia Yan, Bhargava Gopireddy, Read Sprabery, Josep Torrellas, Christopher W. Fletcher Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2019 Highest ranked paper in double-blind review process IEEE Micro Top Picks 2020 [paper] [conference talk] [open-source release]
SecDir: Secure Directories to Defeat Directory Side Channel Attacks
Mengjia Yan, Jen-Yang Wen, Christopher W. Fletcher, Josep Torrellas Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2019 [paper]
gem5-Approxilyzer: an Open Source Tool for Application-level Soft Error Analysis
Radha Venkatagiri, Khalique Ahmed, Abdulrahman Mahmoud, Sasa Misailovic, Darko Marinov, Christopher W. Fletcher, and Sarita V. Adve Appears in the Proceedings of the IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), 2019 [paper] [open-source release]
Buffets: An Efficient and Composable Storage Idiom for Explicit Decoupled Data Orchestration
Michael Pellauer, Yakun Sophia Shao, Jason Clemons, Neal Crago, Kartik Hegde, Rangarajan Venkatesan, Stephen W. Keckler, Christopher W. Fletcher, Joel Emer Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2019 IEEE Micro Top Picks 2020 Honorable Mention [paper] [lightning talk] [open-source release]
Minotaur: Adapting Software Testing Techniques for Hardware Errors
Abdulrahman Mahmoud, Radha Venkatagiri, Khalique Ahmed, Sasa Misailovic, Darko Marinov, Christopher W. Fletcher, Sarita V. Adve Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2019 [paper] [conference talk]
Data Oblivious ISA Extensions for Side Channel-Resistant and High Performance Computing
Jiyong Yu, Lucas Hsiung, Mohamad El Hajj, Christopher W. Fletcher Appears in the Proceedings of the Internet Society Network and Distributed System Security Symposium (NDSS), 2019 Distinguished Paper Finalist CSAW Applied Research Competition Finalist IEEE Micro Top Picks 2020 [paper] [conference talk] [open-source release]
Attack Directories, Not Caches: Side Channel Attacks in a Non-Inclusive World
Mengjia Yan, Read Sprabery, Bhargava Gopireddy, Christopher W. Fletcher, Roy Campbell, Josep Torrellas Appears in the Proceedings of the IEEE Symposium on Security and Privacy (Oakland/SP), 2019 [paper] [conference talk]
InvisiSpec: Making Speculative Execution Invisible in the Cache Hierarchy
Mengjia Yan, Jiho Choi, Dimitrios Skarlatos, Adam Morrison, Christopher W. Fletcher, Josep Torrellas Appears in the Proceedings of the ACM/IEEE International Symposium on Microarchitecture (MICRO), 2018 IEEE Micro Top Picks 2019 Honorable Mention [paper] [lightning talk] [corrigendum] [corrected paper] [open-source release]
Morph: Flexible Acceleration for 3D CNN-based Video Understanding
Kartik Hegde, Rohit Agrawal, Yulun Yao, Christopher W. Fletcher Appears in the Proceedings of the ACM/IEEE International Symposium on Microarchitecture (MICRO), 2018 [paper]
UCNN: Exploiting Computational Reuse in Deep Neural Networks via Weight Repetition
Kartik Hegde, Jiyong Yu, Rohit Agrawal, Mengjia Yan, Michael Pellauer, Christopher W. Fletcher Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2018 [paper] [lightning talk]
Path ORAM: An Extremely Simple Oblivious RAM Protocol
Emil Stefanov, Marten van Dijk, Elaine Shi, T-H Hubert Chan, Christopher W. Fletcher, Ling Ren, Xiangyao Yu, Srinivas Devadas Appears in the Journal of the ACM (JACM), 2018 [paper]
ZeroTrace: Oblivious Memory Primitives from Intel SGX
Sajin Sasy, Sergey Gorbunov, Christopher W. Fletcher Appears in the Proceedings of the Internet Society Network and Distributed System Security Symposium (NDSS), 2018 [paper] [open-source release]
Design and Implementation of the Ascend Secure Processor
Ling Ren, Christopher W. Fletcher, Albert Kwon; Marten van Dijk; Srinivas Devadas Appears in the IEEE Transactions on Dependable and Secure Computing (TDSC), 2017 [paper]
Asymptotically tight bounds for composing ORAM with PIR
Kartik Nayak, Ling Ren, Christopher W. Fletcher, Ittai Abraham, Benny Pinkas Appears in the Proceedings of the IACR International Conference on Practice and Theory of Public-Key Cryptography (PKC), 2017 [paper]
HOP: Hardware makes Obfuscation Practical
Kartik Nayak, Christopher W. Fletcher, Ling Ren, Nishanth Chandran, Satya Lokam, Elaine Shi, Vipul Goyal Appears in the Proceedings of the Internet Society Network and Distributed System Security Symposium (NDSS), 2017 [paper] [open-source release]
Onion ORAM: A Constant Bandwidth Blowup Oblivious RAM
Srinivas Devadas, Marten van Dijk, Christopher W. Fletcher*, Ling Ren*, Elaine Shi, Daniel Wichs (*: Co-lead authors.) Appears in the Proceedings of the IACR Theory of Cryptography Conference (TCC), 2016 [paper] [conference talk]
Constants Count: Practical Improvements to Oblivious RAM
Ling Ren, Christopher W. Fletcher, Albert Kwon, Emil Stefanov, Elaine Shi, Marten van Dijk, Srinivas Devadas Appears in the Proceedings of the USENIX Security Symposium (Security), 2015 [paper]
PrORAM: Dynamic Prefetcher for Oblivious RAM
Xiangyao Yu, Syed Kamran Haider, Ling Ren, Christopher W. Fletcher, Albert Kwon, Marten van Dijk, Srinivas Devadas Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2015 [paper]
A Low-Latency, Low-Area Hardware Oblivious RAM Controller
Christopher W. Fletcher, Ling Ren, Albert Kwon, Marten van Dijk, Emil Stefanov, Dimitrios Serpanos, Srinivas Devadas Appears in the Proceedings of the IEEE International Symposium On Field-Programmable Custom Computing Machines (FCCM), 2015 [paper] [open-source release]
Freecursive ORAM: [Nearly] Free Recursion and Integrity Verification for Position-based Oblivious RAM
Christopher W. Fletcher, Ling Ren, Albert Kwon, Marten van Dijk, Srinivas Devadas Appears in the Proceedings of the ACM Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2015 [paper]
Suppressing the Oblivious RAM Timing Channel While Making Information Leakage and Program Efficiency Trade-offs
Christopher W. Fletcher, Ling Ren, Xiangyao Yu, Marten van Dijk, Omer Khan, Srinivas Devadas Appears in the Proceedings of the IEEE International Symposium on High-Performance Computer Architecture (HPCA), 2014 [paper]
Path ORAM: An Extremely Simple Oblivious RAM Protocol
Emil Stefanov, Marten van Dijk, Elaine Shi, Christopher W. Fletcher, Ling Ren, Xiangyao Yu, Srinivas Devadas Appears in the Proceedings of the ACM Conference on Computer and Communications Security (CCS), 2013 Best Student Paper Award Top Picks in Hardware & Embedded Security 2018 Test of Time Award [paper]
Generalized External Interaction with Tamper-Resistant Hardware with Bounded Information Leakage
Xiangyao Yu, Christopher W. Fletcher, Ling Ren, Marten van Dijk, Srinivas Devadas Appears in the Proceedings of the ACM Cloud Computing Security Workshop (CCSW), 2013 [paper]
A Framework to Accelerate Sequential Programs on Homogeneous Multicores
Christopher W. Fletcher, Rachael Harding, Omer Khan, Srinivas Devadas Appears in the Proceedings of the IFIP/IEEE International Conference on Very Large Scale Integration (VLSI-SOC), 2013 [paper]
Integrity Verification for Path Oblivious-RAM
Ling Ren, Christopher W. Fletcher, Xiangyao Yu, Marten van Dijk, Srinivas Devadas Appears in the Proceedings of the IEEE High Performance Extreme Computing Virtual Conference (HPEC), 2013 [paper]
Design Space Exploration and Optimization of Path Oblivious RAM in Secure Processors
Ling Ren, Xiangyao Yu, Christopher W. Fletcher, Marten van Dijk, Srinivas Devadas Appears in the Proceedings of the ACM/IEEE International Symposium on Computer Architecture (ISCA), 2013 [paper]
Towards an Interpreter for Efficient Encrypted Computation
Christopher W. Fletcher, Marten van Dijk, Srinivas Devadas Appears in the Proceedings of the ACM Cloud Computing Security Workshop (CCSW), 2012 [paper]
A Secure Processor Architecture for Encrypted Computation on Untrusted Programs
Christopher W. Fletcher, Marten van Dijk, Srinivas Devadas Appears in the Proceedings of the ACM Workshop on Scalable Trusted Computing (STC), 2012 [paper]
HORNET: a cycle-level multicore simulator
Pengju Ren, Mieszko Lis, Myong Hyon Cho, Keun Sup Shim, Christopher W. Fletcher, Omer Khan, Nanning Zheng, Srinivas Devadas Appears in the IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems (TCAD), 2012 [paper]
A Low-overhead Dynamic Optimization Framework on Multicores (short paper)
Christopher W. Fletcher, Rachael Harding, Omer Khan, Srinivas Devadas Appears in the Proceedings of the International Conference on Parallel Architectures and Compilation Techniques (PACT), 2012 [paper]
Exploring Many-core Design Templates for FPGAs and ASICs
Ilia Lebedev, Christopher W. Fletcher, Shaoyi Cheng, James Martin, Austin Doupnik, Daniel Burke, Mingjie Lin, John Wawrzynek Appears in the Proceedings of the International Journal of Reconfigurable Computing (IJRC), 2012 [paper]
Scalable Accurate Multicore Simulation in the 1000 core era
Mieszko Lis, Pengju Ren, Myong Hyon Cho, Keun Sup Shim, Christopher W. Fletcher, Omer Khan, Srinivas Devadas Appears in the Proceedings of the International Symposium on Performance Analysis of Systems and Software (ISPASS), 2011 [paper]
Brief Announcement: Distributed Shared Memory based on Computation Migration (short paper)
Mieszko Lis, Keun Sup Shim, Myong Hyon Cho, Christopher W. Fletcher, Michel Kinsy, Ilia Lebedev, Omer Khan, Srinivas Devadas Appears in the Proceedings of the ACM Symposium on Parallelism in Algorithms and Architectures (SPAA), 2011 [paper]
Bridging the GPGPU-FPGA Efficiency Gap (short paper)
Christopher W. Fletcher, Ilia Lebedev, Narges B. Asadi, Daniel R. Burke, John Wawrzynek Appears in the Proceedings of the International Symposium on Field-Programmable Gate Arrays (FPGA), 2011 [paper]
MARC: A Many-Core Approach to Reconfigurable Computing
Ilia Lebedev, Shaoyi Cheng, Austin Doupnik, James Martin, Christopher W. Fletcher, Daniel Burke, Mingjie Lin, John Wawrzynek Appears in the Proceedings of the International Conference on Reconfigurable Computing and FPGAs (ReConFig), 2010 [paper]
ParaLearn: A Massively Parallel, Scalable System for Learning Interaction Networks on FPGAs
Narges B. Asadi*, Christopher W. Fletcher*, Greg Gibeling, Karen Sachs, Eric Glass, Daniel Burke, Zoey Zhou, John Wawrzynek, Wing H. Wong, Garry P. Nolan (*: Co-lead authors.) Appears in the Proceedings of the International Conference on Supercomputing (ICS), 2010 Best Student Paper Award [paper] [slides]
Theses
Oblivious RAM: From Theory to Practice Christopher W. Fletcher
PhD thesis George M. Sprowls Award for outstanding PhD thesis in CS at MIT [thesis]
Ascend: An Architecture for Performing Secure Computation on Encrypted Data Christopher W. Fletcher
SM thesis [thesis]
Patents
Technique for secure computation Srinivas Devadas, Christopher W. Fletcher, Marten Van Dijk
Patent No. 8909967 (Note: there is currently a bug where only Marten is listed as inventor. The lawyers are fixing it...)
Funding
We thank NSF, DARPA, Intel, Apple and Google for their generous support!