PVAC: A RowHammer Mitigation Architecture Exploiting Per-victim-row Counting

Computer Science > Cryptography and Security [Submitted on 22 Apr 2026] PVAC: A RowHammer Mitigation Architecture Exploiting Per-victim-row Counting Jumin Kim, Seungmin Baek, Hwayong Nam, Minbok Wi, Nam Sung Kim, Jung Ho Ahn As DRAM scaling exacerbates RowHammer, DDR5 introduces per-row activation counting (PRAC) to track aggressor activity. However, PRAC indiscriminately increments counters on every activation -- including benign refreshes -- while relying solely on explicit RFM operations for resets. Consequently, counters saturate even in an idle bank, triggering cascading mitigations and degrading performance. This vulnerability arises from a fundamental mismatch: PRAC tracks the aggressor but aims to protect the victim. We present Per-Victim-row hAmmered Counting (PVAC), a victim-based counting mechanism that aligns the counter semantics with the physical disturbance mechanism of RowHammer. PVAC increments the counters of victim rows, resets the activated row, and naturally bounds counter values under normal refresh. To enable efficient victim-based updates, PVAC employs a dedicated counter subarray (CSA) that performs all counter resets and increments concurrently with normal accesses, without timing overhead. We further devise an energy-efficient CSA layout that minimizes refresh-induced counter accesses. Through victim-based counting, PVAC supports higher hammering tolerance than PRAC while maintaining the same worst-case safety guarantee. Across benign workloads and adversarial attack patterns, PVAC avoids spurious Alerts, eliminates PRAC timing penalties, and achieves higher performance and lower energy consumption than prior PRAC-based defenses. Comments: 16 pages, 13 figures, accepted at ISCA 2026, slightly extended Subjects: Cryptography and Security (cs.CR); Hardware Architecture (cs.AR) Cite as: arXiv:2604.20576 [cs.CR]   (or arXiv:2604.20576v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2604.20576 Focus to learn more Submission history From: Jung Ho Ahn [view email] [v1] Wed, 22 Apr 2026 13:56:38 UTC (428 KB) Access Paper: HTML (experimental) view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-04 Change to browse by: cs cs.AR 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?)