dfence: Fine-Grained Speculation Barriers for Efficient and Effective Hardware-Software Protection in the Spectre Era (Extended Version)

Computer Science > Cryptography and Security [Submitted on 6 Aug 2026] dfence: Fine-Grained Speculation Barriers for Efficient and Effective Hardware-Software Protection in the Spectre Era (Extended Version) Davide Davoli, Marton Bognar, Lesly-Ann Daniel, Benjamin Grégoire, Frank Piessens, Tamara Rezk Speculative execution attacks such as Spectre-PHT and Spectre-STL remain a critical security concern in modern processors. While software-based mitigations like Speculative Load Hardening (SLH) offer effective protection against Spectre-PHT, they are limited in scope and require software-managed speculative masks, which can be error-prone and costly. Defenses against Spectre-STL, such as the Speculative Store Bypass Disable bit (SSBD), incur additional performance overhead and lack fine-grained control. In this work, we introduce dfence, a new CPU instruction that generalizes SLH to mitigate both Spectre-PHT and Spectre-STL with minimal hardware support. dfence enables developers to annotate sensitive registers, with the hardware ensuring that these values do not leak transiently. We implement dfence in the Proteus CPU and evaluate its security and performance, demonstrating less than 1% average performance overhead for our benchmarks. In addition, to support easy and secure adoption, we design a type system that statically verifies the correct placement of dfence instructions in code. Subjects: Cryptography and Security (cs.CR) Cite as: arXiv:2608.06124 [cs.CR]   (or arXiv:2608.06124v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2608.06124 Focus to learn more Related DOI: https://doi.org/10.1145/3830454.3832748 Focus to learn more Submission history From: Davide Davoli [view email] [v1] Thu, 6 Aug 2026 14:55:00 UTC (102 KB) Access Paper: view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-08 Change to browse by: cs References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)