[{"language":[{"iso":"eng"}],"date_updated":"2023-09-26T13:23:58Z","doi":"10.1145/3053687","department":[{"_id":"27"},{"_id":"518"}],"publication_identifier":{"issn":["1936-7406"]},"publication_status":"published","project":[{"_id":"1","grant_number":"160364472","name":"SFB 901"},{"_id":"4","name":"SFB 901 - Project Area C"},{"grant_number":"160364472","name":"SFB 901 - Subproject C2","_id":"14"},{"_id":"34","grant_number":"610996","name":"Self-Adaptive Virtualisation-Aware High-Performance/Low-Energy Heterogeneous System Architectures"},{"_id":"52","name":"Computing Resources Provided by the Paderborn Center for Parallel Computing"}],"title":"Efficient Branch and Bound on FPGAs Using Work Stealing and Instance-Specific Designs","page":"24:1-24:23","year":"2017","citation":{"bibtex":"@article{Riebler_Lass_Mittendorf_Löcke_Plessl_2017, title={Efficient Branch and Bound on FPGAs Using Work Stealing and Instance-Specific Designs}, volume={10}, DOI={10.1145/3053687}, number={3}, journal={ACM Transactions on Reconfigurable Technology and Systems (TRETS)}, publisher={Association for Computing Machinery (ACM)}, author={Riebler, Heinrich and Lass, Michael and Mittendorf, Robert and Löcke, Thomas and Plessl, Christian}, year={2017}, pages={24:1-24:23} }","mla":"Riebler, Heinrich, et al. “Efficient Branch and Bound on FPGAs Using Work Stealing and Instance-Specific Designs.” ACM Transactions on Reconfigurable Technology and Systems (TRETS), vol. 10, no. 3, Association for Computing Machinery (ACM), 2017, p. 24:1-24:23, doi:10.1145/3053687.","chicago":"Riebler, Heinrich, Michael Lass, Robert Mittendorf, Thomas Löcke, and Christian Plessl. “Efficient Branch and Bound on FPGAs Using Work Stealing and Instance-Specific Designs.” ACM Transactions on Reconfigurable Technology and Systems (TRETS) 10, no. 3 (2017): 24:1-24:23. https://doi.org/10.1145/3053687.","apa":"Riebler, H., Lass, M., Mittendorf, R., Löcke, T., & Plessl, C. (2017). Efficient Branch and Bound on FPGAs Using Work Stealing and Instance-Specific Designs. ACM Transactions on Reconfigurable Technology and Systems (TRETS), 10(3), 24:1-24:23. https://doi.org/10.1145/3053687","ama":"Riebler H, Lass M, Mittendorf R, Löcke T, Plessl C. Efficient Branch and Bound on FPGAs Using Work Stealing and Instance-Specific Designs. ACM Transactions on Reconfigurable Technology and Systems (TRETS). 2017;10(3):24:1-24:23. doi:10.1145/3053687","ieee":"H. Riebler, M. Lass, R. Mittendorf, T. Löcke, and C. Plessl, “Efficient Branch and Bound on FPGAs Using Work Stealing and Instance-Specific Designs,” ACM Transactions on Reconfigurable Technology and Systems (TRETS), vol. 10, no. 3, p. 24:1-24:23, 2017, doi: 10.1145/3053687.","short":"H. Riebler, M. Lass, R. Mittendorf, T. Löcke, C. Plessl, ACM Transactions on Reconfigurable Technology and Systems (TRETS) 10 (2017) 24:1-24:23."},"type":"journal_article","intvolume":" 10","_id":"18","issue":"3","keyword":["coldboot"],"publication":"ACM Transactions on Reconfigurable Technology and Systems (TRETS)","file_date_updated":"2018-11-02T16:04:14Z","author":[{"last_name":"Riebler","id":"8961","first_name":"Heinrich","full_name":"Riebler, Heinrich"},{"last_name":"Lass","id":"24135","first_name":"Michael","orcid":"0000-0002-5708-7632","full_name":"Lass, Michael"},{"last_name":"Mittendorf","first_name":"Robert","full_name":"Mittendorf, Robert"},{"last_name":"Löcke","first_name":"Thomas","full_name":"Löcke, Thomas"},{"first_name":"Christian","orcid":"0000-0001-5728-9982","full_name":"Plessl, Christian","last_name":"Plessl","id":"16153"}],"quality_controlled":"1","publisher":"Association for Computing Machinery (ACM)","file":[{"access_level":"closed","file_name":"a24-riebler.pdf","date_created":"2018-11-02T16:04:14Z","relation":"main_file","success":1,"content_type":"application/pdf","date_updated":"2018-11-02T16:04:14Z","creator":"ups","file_id":"5322","file_size":2131617}],"volume":10,"date_created":"2017-07-25T14:17:32Z","status":"public","has_accepted_license":"1","abstract":[{"lang":"eng","text":"Branch and bound (B&B) algorithms structure the search space as a tree and eliminate infeasible solutions early by pruning subtrees that cannot lead to a valid or optimal solution. Custom hardware designs significantly accelerate the execution of these algorithms. In this article, we demonstrate a high-performance B&B implementation on FPGAs. First, we identify general elements of B&B algorithms and describe their implementation as a finite state machine. Then, we introduce workers that autonomously cooperate using work stealing to allow parallel execution and full utilization of the target FPGA. Finally, we explore advantages of instance-specific designs that target a specific problem instance to improve performance.\r\n\r\nWe evaluate our concepts by applying them to a branch and bound problem, the reconstruction of corrupted AES keys obtained from cold-boot attacks. The evaluation shows that our work stealing approach is scalable with the available resources and provides speedups proportional to the number of workers. Instance-specific designs allow us to achieve an overall speedup of 47 × compared to the fastest implementation of AES key reconstruction so far. Finally, we demonstrate how instance-specific designs can be generated just-in-time such that the provided speedups outweigh the additional time required for design synthesis."}],"ddc":["000"],"user_id":"15278"},{"type":"conference","year":"2014","citation":{"ieee":"H. Riebler, T. Kenter, C. Plessl, and C. Sorge, “Reconstructing AES Key Schedules from Decayed Memory with FPGAs,” in Proceedings of Field-Programmable Custom Computing Machines (FCCM), 2014, pp. 222–229, doi: 10.1109/FCCM.2014.67.","short":"H. Riebler, T. Kenter, C. Plessl, C. Sorge, in: Proceedings of Field-Programmable Custom Computing Machines (FCCM), IEEE, 2014, pp. 222–229.","bibtex":"@inproceedings{Riebler_Kenter_Plessl_Sorge_2014, title={Reconstructing AES Key Schedules from Decayed Memory with FPGAs}, DOI={10.1109/FCCM.2014.67}, booktitle={Proceedings of Field-Programmable Custom Computing Machines (FCCM)}, publisher={IEEE}, author={Riebler, Heinrich and Kenter, Tobias and Plessl, Christian and Sorge, Christoph}, year={2014}, pages={222–229} }","mla":"Riebler, Heinrich, et al. “Reconstructing AES Key Schedules from Decayed Memory with FPGAs.” Proceedings of Field-Programmable Custom Computing Machines (FCCM), IEEE, 2014, pp. 222–29, doi:10.1109/FCCM.2014.67.","chicago":"Riebler, Heinrich, Tobias Kenter, Christian Plessl, and Christoph Sorge. “Reconstructing AES Key Schedules from Decayed Memory with FPGAs.” In Proceedings of Field-Programmable Custom Computing Machines (FCCM), 222–29. IEEE, 2014. https://doi.org/10.1109/FCCM.2014.67.","ama":"Riebler H, Kenter T, Plessl C, Sorge C. Reconstructing AES Key Schedules from Decayed Memory with FPGAs. In: Proceedings of Field-Programmable Custom Computing Machines (FCCM). IEEE; 2014:222-229. doi:10.1109/FCCM.2014.67","apa":"Riebler, H., Kenter, T., Plessl, C., & Sorge, C. (2014). Reconstructing AES Key Schedules from Decayed Memory with FPGAs. Proceedings of Field-Programmable Custom Computing Machines (FCCM), 222–229. https://doi.org/10.1109/FCCM.2014.67"},"page":"222-229","_id":"377","publisher":"IEEE","author":[{"id":"8961","last_name":"Riebler","full_name":"Riebler, Heinrich","first_name":"Heinrich"},{"full_name":"Kenter, Tobias","first_name":"Tobias","id":"3145","last_name":"Kenter"},{"first_name":"Christian","full_name":"Plessl, Christian","orcid":"0000-0001-5728-9982","last_name":"Plessl","id":"16153"},{"full_name":"Sorge, Christoph","first_name":"Christoph","last_name":"Sorge"}],"quality_controlled":"1","keyword":["coldboot"],"publication":"Proceedings of Field-Programmable Custom Computing Machines (FCCM)","file_date_updated":"2018-03-20T07:14:20Z","file":[{"relation":"main_file","success":1,"date_updated":"2018-03-20T07:14:20Z","content_type":"application/pdf","creator":"florida","file_id":"1397","file_size":1003907,"access_level":"closed","date_created":"2018-03-20T07:14:20Z","file_name":"377-FCCM14.pdf"}],"has_accepted_license":"1","status":"public","date_created":"2017-10-17T12:42:05Z","abstract":[{"lang":"eng","text":"In this paper, we study how AES key schedules can be reconstructed from decayed memory. This operation is a crucial and time consuming operation when trying to break encryption systems with cold-boot attacks. In software, the reconstruction of the AES master key can be performed using a recursive, branch-and-bound tree-search algorithm that exploits redundancies in the key schedule for constraining the search space. In this work, we investigate how this branch-and-bound algorithm can be accelerated with FPGAs. We translated the recursive search procedure to a state machine with an explicit stack for each recursion level and create optimized datapaths to accelerate in particular the processing of the most frequently accessed tree levels. We support two different decay models, of which especially the more realistic non-idealized asymmetric decay model causes very high runtimes in software. Our implementation on a Maxeler dataflow computing system outperforms a software implementation for this model by up to 27x, which makes cold-boot attacks against AES practical even for high error rates."}],"ddc":["040"],"user_id":"15278","language":[{"iso":"eng"}],"date_updated":"2023-09-26T13:33:50Z","doi":"10.1109/FCCM.2014.67","department":[{"_id":"27"},{"_id":"518"},{"_id":"78"}],"project":[{"_id":"1","name":"SFB 901","grant_number":"160364472"},{"_id":"14","grant_number":"160364472","name":"SFB 901 - Subprojekt C2"},{"_id":"4","name":"SFB 901 - Project Area C"},{"grant_number":"610996","name":"Self-Adaptive Virtualisation-Aware High-Performance/Low-Energy Heterogeneous System Architectures","_id":"34"}],"title":"Reconstructing AES Key Schedules from Decayed Memory with FPGAs"},{"language":[{"iso":"ger"}],"citation":{"bibtex":"@book{Riebler_2013, title={Identifikation und Wiederherstellung von kryptographischen Schlüsseln mit FPGAs}, publisher={Universität Paderborn}, author={Riebler, Heinrich}, year={2013} }","mla":"Riebler, Heinrich. Identifikation und Wiederherstellung von kryptographischen Schlüsseln mit FPGAs. Universität Paderborn, 2013.","chicago":"Riebler, Heinrich. Identifikation und Wiederherstellung von kryptographischen Schlüsseln mit FPGAs. Universität Paderborn, 2013.","apa":"Riebler, H. (2013). Identifikation und Wiederherstellung von kryptographischen Schlüsseln mit FPGAs. Universität Paderborn.","ama":"Riebler H. Identifikation und Wiederherstellung von kryptographischen Schlüsseln mit FPGAs. Universität Paderborn; 2013.","ieee":"H. Riebler, Identifikation und Wiederherstellung von kryptographischen Schlüsseln mit FPGAs. Universität Paderborn, 2013.","short":"H. Riebler, Identifikation und Wiederherstellung von kryptographischen Schlüsseln mit FPGAs, Universität Paderborn, 2013."},"type":"mastersthesis","year":"2013","date_updated":"2022-01-06T07:01:46Z","_id":"521","date_created":"2017-10-17T12:42:34Z","project":[{"_id":"1","name":"SFB 901"},{"name":"SFB 901 - Subprojekt C1","_id":"13"},{"name":"SFB 901 - Subprojekt C2","_id":"14"},{"_id":"4","name":"SFB 901 - Project Area C"}],"status":"public","keyword":["coldboot"],"department":[{"_id":"27"},{"_id":"518"}],"author":[{"full_name":"Riebler, Heinrich","first_name":"Heinrich","id":"8961","last_name":"Riebler"}],"publisher":"Universität Paderborn","user_id":"477","title":"Identifikation und Wiederherstellung von kryptographischen Schlüsseln mit FPGAs"},{"title":"FPGA-accelerated Key Search for Cold-Boot Attacks against AES","project":[{"grant_number":"160364472","name":"SFB 901","_id":"1"},{"grant_number":"160364472","name":"SFB 901 - Subprojekt C2","_id":"14"},{"name":"SFB 901 - Subproject C1","_id":"13"},{"name":"SFB 901 - Project Area C","_id":"4"},{"name":"Self-Adaptive Virtualisation-Aware High-Performance/Low-Energy Heterogeneous System Architectures","grant_number":"610996","_id":"34"}],"department":[{"_id":"27"},{"_id":"518"},{"_id":"78"}],"doi":"10.1109/FPT.2013.6718394","date_updated":"2023-09-26T13:37:35Z","language":[{"iso":"eng"}],"ddc":["040"],"user_id":"15278","abstract":[{"lang":"eng","text":"Cold-boot attacks exploit the fact that DRAM contents are not immediately lost when a PC is powered off. Instead the contents decay rather slowly, in particular if the DRAM chips are cooled to low temperatures. This effect opens an attack vector on cryptographic applications that keep decrypted keys in DRAM. An attacker with access to the target computer can reboot it or remove the RAM modules and quickly copy the RAM contents to non-volatile memory. By exploiting the known cryptographic structure of the cipher and layout of the key data in memory, in our application an AES key schedule with redundancy, the resulting memory image can be searched for sections that could correspond to decayed cryptographic keys; then, the attacker can attempt to reconstruct the original key. However, the runtime of these algorithms grows rapidly with increasing memory image size, error rate and complexity of the bit error model, which limits the practicability of the approach.In this work, we study how the algorithm for key search can be accelerated with custom computing machines. We present an FPGA-based architecture on a Maxeler dataflow computing system that outperforms a software implementation up to 205x, which significantly improves the practicability of cold-attacks against AES."}],"has_accepted_license":"1","status":"public","date_created":"2017-10-17T12:42:35Z","quality_controlled":"1","author":[{"last_name":"Riebler","id":"8961","first_name":"Heinrich","full_name":"Riebler, Heinrich"},{"last_name":"Kenter","id":"3145","first_name":"Tobias","full_name":"Kenter, Tobias"},{"last_name":"Sorge","full_name":"Sorge, Christoph","first_name":"Christoph"},{"first_name":"Christian","full_name":"Plessl, Christian","orcid":"0000-0001-5728-9982","last_name":"Plessl","id":"16153"}],"publisher":"IEEE","publication":"Proceedings of the International Conference on Field-Programmable Technology (FPT)","keyword":["coldboot"],"file_date_updated":"2018-03-15T10:36:08Z","file":[{"creator":"florida","file_id":"1294","file_size":822680,"success":1,"relation":"main_file","date_updated":"2018-03-15T10:36:08Z","content_type":"application/pdf","file_name":"528-plessl13_fpt.pdf","date_created":"2018-03-15T10:36:08Z","access_level":"closed"}],"_id":"528","citation":{"short":"H. Riebler, T. Kenter, C. Sorge, C. Plessl, in: Proceedings of the International Conference on Field-Programmable Technology (FPT), IEEE, 2013, pp. 386–389.","ieee":"H. Riebler, T. Kenter, C. Sorge, and C. Plessl, “FPGA-accelerated Key Search for Cold-Boot Attacks against AES,” in Proceedings of the International Conference on Field-Programmable Technology (FPT), 2013, pp. 386–389, doi: 10.1109/FPT.2013.6718394.","apa":"Riebler, H., Kenter, T., Sorge, C., & Plessl, C. (2013). FPGA-accelerated Key Search for Cold-Boot Attacks against AES. Proceedings of the International Conference on Field-Programmable Technology (FPT), 386–389. https://doi.org/10.1109/FPT.2013.6718394","ama":"Riebler H, Kenter T, Sorge C, Plessl C. FPGA-accelerated Key Search for Cold-Boot Attacks against AES. In: Proceedings of the International Conference on Field-Programmable Technology (FPT). IEEE; 2013:386-389. doi:10.1109/FPT.2013.6718394","chicago":"Riebler, Heinrich, Tobias Kenter, Christoph Sorge, and Christian Plessl. “FPGA-Accelerated Key Search for Cold-Boot Attacks against AES.” In Proceedings of the International Conference on Field-Programmable Technology (FPT), 386–89. IEEE, 2013. https://doi.org/10.1109/FPT.2013.6718394.","mla":"Riebler, Heinrich, et al. “FPGA-Accelerated Key Search for Cold-Boot Attacks against AES.” Proceedings of the International Conference on Field-Programmable Technology (FPT), IEEE, 2013, pp. 386–89, doi:10.1109/FPT.2013.6718394.","bibtex":"@inproceedings{Riebler_Kenter_Sorge_Plessl_2013, title={FPGA-accelerated Key Search for Cold-Boot Attacks against AES}, DOI={10.1109/FPT.2013.6718394}, booktitle={Proceedings of the International Conference on Field-Programmable Technology (FPT)}, publisher={IEEE}, author={Riebler, Heinrich and Kenter, Tobias and Sorge, Christoph and Plessl, Christian}, year={2013}, pages={386–389} }"},"type":"conference","year":"2013","page":"386-389"}]