Cryptography and Security · Cross-listed from cs.PL
ASAP: Assembly-Source Aligned Pseudocode Refinement For Binary Decompilation
Yujian Zhuang, Dehong Gao, Qichao Zhang et al. (+4 more)
Large
language models (LLMs) are increasingly used in binary decompilation to refine the C-like pseudocode produced by traditional rule-based decompilers. While this pseudocode is useful, it is a heuristic and lossy abstraction rather than a faithful copy of the source code. It often contains decompiler errors, especially for aggressively optimized binaries where critical low-level details are obscured. We present ASAP, an assembly-source aligned pseudocode refinement framework for binary decompilation. ASAP learns source-aligned assembly representations from paired source and binary functions using joint function-level and snippet-level contrastive
alignment. A Q-Former then compresses chunk-level assembly features into a fixed number of assembly
tokens that condition the decompilation LLM alongside the decompiler-produced pseudocode. During refinement, we use
stochastic pseudocode masking and a relative assembly-advantage loss to reduce the model's tendency to ignore assembly features and rely only on pseudocode refining. On two decompilation
benchmarks across multiple compiler optimization levels, ASAP improves the average re-execution rate from 64.7% to 71.9% and the average recompilation rate from 91.6% to 96.6% compared with the strongest baseline, offering both a new perspective and a practical solution to binary decompilation.
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All authors Yujian Zhuang, Dehong Gao, Qichao Zhang, Qijing Lai, Jiaxin Wang, Libin Yang, Xiaoyan Cai
Cryptography and Security
Do Defenses Against LLM Extraction Work Across Attacks? A Lifecycle Benchmark of Black-Box Model Extraction
Shuze Liu, Kaixiang Zhao, Runyang Xu et al. (+4 more)
Large
language models (LLMs) deployed through text-only APIs face model extraction risks, as adversaries can collect their responses to train surrogates that reproduce their capabilities. While prior work has developed diverse attacks and defenses, evaluations remain fragmented across access assumptions, model configurations, query budgets, and security objectives, limiting comparability across methods. To address this gap, we introduce a unified
benchmark covering six extraction attacks, ten defenses, and two adaptive attacks that paraphrase or back-translate protected responses before surrogate training. The
benchmark controls model configurations, query data, budgets, and held-out evaluation conditions within each comparison while preserving attack-specific querying and training procedures. We measure surrogate capability, fidelity to the victim, output quality using Rep-4, and query-budget sensitivity; defenses use their own security metrics paired with surrogate performance. For the adaptive attacks, we jointly measure provenance-detector scores and the capability and fidelity of surrogates trained on rewritten responses. The
benchmark thus provides a reproducible basis for comparing extraction methods and their interactions with defenses under text-only access. Code and artifacts are available at https://github.com/sliu11-byte/MEA-Bench.
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All authors Shuze Liu, Kaixiang Zhao, Runyang Xu, Jingzhi Chen, Nathan Wu, Yu Wang, Yushun Dong
Cryptography and Security
SafeDepth: Safety-Aware Token-Level Adaptive Computation
Nizhang Li and Ian G. Harris
Recent studies suggest that not every
token needs to pass through all
Transformer layers, motivating
token-level adaptive models that selectively skip layers to reduce computation. Our experiments show that these execution choices also affect safety: existing
token-level adaptive
reasoning models exhibit higher harmful-response rates than their reference backbones. The safety effects depend on which layers are skipped and whether skipping occurs during
prompt processing or answer generation. We further find that recognizing harmful requests and producing refusals depend on different layer-wise computations. We introduce SafeDepth, a lightweight, plug-in framework that uses selective layer execution to improve both safety and efficiency. SafeDepth learns to retain computations that support safe responses and bypass those that contribute to unsafe generation. A router selects layer execution based on
token representations, layer position, and inference phase, while an adapter supports the skipped paths. We jointly train these modules to reduce computation and harmful responses while preserving performance on benign tasks, targeting a better safety-efficiency trade-off. The pretrained backbone remains frozen throughout, requiring no additional pretraining. Experimental results on Llama-3-8B-Instruct show that SafeDepth reduces computation relative to full-depth inference while largely preserving task performance. Compared with FlexiDepth, it lowers unsafe-response rates across all five harmful-request
benchmarks, with the largest absolute decrease on HarmBench-HJ (from 55.44% to 25.25%), while reducing the XSTest false-refusal rate from 12.0% to 4.0%.
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Cryptography and Security · Cross-listed from cs.AI
Sapien: A Stateful Policy Engine for Autonomous AI Agents
Corinn Tiffany, Wen Zhang, Eugene Bagdasarian et al. (+1 more)
Contextual security defenses prevent AI
agents from taking rogue actions by synthesizing a task-specific policy and enforcing it on the
agent's tool calls. In multi-step tasks, however, which actions are valid often depends on what the
agent has already done and learned. We present Sapien, a policy engine for enforcing stateful contextual policies. A Sapien policy specifies permitted tool-call sequences using a regular expression extended with stateful predicates, deferred policy generation, and scoped semantic checks. We show that Sapien stays within a few percent of an unconstrained
agent's utility. Even if the
agent is fully hijacked, Sapien's policies rule out 93-95% of attacks on AgentDojo and 62-85% on Toolathlon (twice as many as tool allowlists on long-horizon tasks).
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All authors Corinn Tiffany, Wen Zhang, Eugene Bagdasarian, Lillian Tsai
Cryptography and Security
Identity-Bound Governance Under Execution Uncertainty: An Accountability Proof Block for LLM Agent Persistent Halts, with Cryptographic Implementation and Cross-Model Calibration
Marcelo Fernandez
A correctly governed LLM
agent can reach a state in which neither continuing execution nor automatically halting is admissible: the system has detected a persistent failure of its observability or drift-detection layer, but cannot itself decide who has the authority to resume, deny, or recalibrate the deployment. We call this an identity-bound governance event and formalise the mechanism that resolves it. We introduce the Accountability Proof Block (APB): a system-constructed evidence block, a human-supplied decision block, and an ed25519 signature binding both to a registered principal. The system cannot forge the signature, and the principal cannot alter the evidence undetected. We prove four
theorems: Protocol-Bounded Governance Completeness, Non-Repudiability, Impossibility of Anonymous Re-Authorization, and Finite-Time APB Construction Termination. The implementation uses RFC 8785 JSON canonicalization and a UUID4-based replay predicate. Empirically, governance completeness holds over 3,812 halt events with zero unresolved cases; the verifier detects 100% of 1,800 attacks across 9
adversarial vectors; a k-of-n multi-principal variant shows 0 false acceptances in 2,000 single-key capture attempts. A study of six open LLMs finds the drift threshold T* stable within model (sigma/T* < 2%) but varying across models, refuting size-monotonicity: the largest model did not drift. T* must therefore be measured per deployment, and the APB is the vehicle by which that threshold yields accountable authority transfer.
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Cryptography and Security
Made to Measure: Designing Image Watermarks to Specification
Mingzhe Li, Yuefeng Peng, Kejing Xia et al. (+3 more)
Image watermarking supports provenance and attribution by
embedding verifiable identity information into images. Practical deployments, however, must jointly satisfy requirements for attack resistance, false-positive rate (FPR), image quality, and latency. Existing watermarking methods are robust to different classes of transformations, so combining complementary methods can provide broader protection than any single watermark. Such composition is challenging, as additional fragments increase distortion and decoding cost and must share the same FPR budget. Therefore, we propose **TAILOR**, a request-conditioned watermark composition framework with three stages: (1) *offline characterization* measures fragment recovery, distortion, and runtime as response curves over
embedding strength; (2) *joint configuration selection* encodes the request as an SMT model over these curves and solves for the lowest-distortion composition of fragments, strengths, order, and
geometric recovery; and (3) *live calibration* validates the selected configuration on the user's images and refines predictions that fail to transfer. Experimental results across 7,321 distinct requests spanning five scenarios and 20 attack settings show that **TAILOR** achieves **96.21%** scenario-averaged request satisfaction with a mean PSNR of **41.02 dB**, outperforming existing methods in robustness while achieving consistently better image quality. Code is available at [https://github.com/aaFrostnova/Tailor](https://github.com/aaFrostnova/Tailor).
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All authors Mingzhe Li, Yuefeng Peng, Kejing Xia, Pranav Jeyakumar, Ruolan Leslie Famularo, Shiqing Ma
Cryptography and Security
Crossing the Cyber Divide: Sim-to-Sim and Sim-to-Real Transfer for RL Agents
Sabrina Saika, Yinuo Du and Aritran Piplai
Cyber attack
agents are typically trained and evaluated within a single simulator, making it unclear whether learned policies transfer beyond the environments in which they were developed. This limitation hinders both deployment and fair comparison, as cyber simulators differ substantially in their state representations, observation models, and action spaces. In this paper, we study policy transfer across cyber environments and argue that simulator-to-simulator and simulator-to-real transfer can be viewed as instances of the same underlying
alignment problem. We propose a framework that separates state
alignment from action translation, enabling a policy trained in one environment to operate in another without retraining. We evaluate transfer across four cyber platforms, CyberBattleSim, NetSecGame, CyberWheel, and NASim, including emulated deployments in NASim. Our experiments show that zero-shot transfer is feasible, fully preserving source-policy performance in closely aligned environments and achieving 45.2% win rates when transferring policies whose source performance is 60.5%. In emulated virtual machine environments, transferred policies exhibit a Jensen-Shannon divergence of 0.085 from native policies, indicating strong behavioral similarity. Code and
benchmarks are available at: https://anonymous.4open.science/r/RL-Transfer-between-env-4F47/.
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Cryptography and Security
Progressive-Resolution Secure Aggregation for Federated Learning
Seyed Mohammad Azimi-Abarghouyi
Secure aggregation lets a server recover an aggregate of client updates without observing any individual update, but conventional protocols fix the aggregate precision when clients upload. We introduce and formulate a new progressive-resolution secure-aggregation functionality in which clients upload once and successively finer resolutions of the same aggregate can later be authorized without renewed client participation. To realize this functionality, we propose progressive-resolution secure aggregation (PSA): each clipped, dithered update is represented by compatible nested-
lattice digits; separately releasable layers are protected by secure aggregation and an additional aggregate pad that remains unavailable to the server until a non-colluding release controller authorizes that layer.
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Cryptography and Security · Cross-listed from cs.AI
Backdoor Purification for LoRA-Tuned LLMs via Null-Space Projection
Jianwei Li and Jung-Eun Kim
With the rapid adoption of large
language models (LLMs) and parameter-efficient fine-tuning (PEFT) methods, the risk of backdoor attacks has become more severe. Existing backdoor purification methods typically rely on at least one of the strong assumptions, such as prior knowledge of triggers, access to clean references, or aggressive retraining, and they often lack comprehensive evaluations. These constraints substantially limit their practical applicability. To overcome these challenges, our work proposes purifying LoRA-tuned LLMs without these assumptions and even without post-hoc retraining of the suspect parameters. Our objective is to significantly reduce the attack success rates (ASR) while preserving both (i) the base model's general capabilities and (ii) the new downstream skills learned through the adapter. Through a series of ablation studies, we progressively scale our approach from a single layer in a text classification setting to a full-parameter LLM in the generative task. Through careful data curation and feature approximation, we extract high-fidelity backdoor directions and, for each layer or head, construct orthogonal null spaces in both the input and output channels, onto which the LoRA updates are projected. Empirically, our null-space projection method reduces the ASR from nearly 100% to less than 10%, while preserving the base model's benign performance and the adapter's learned abilities during downstream task adaptation.
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Cryptography and Security · Cross-listed from cs.AI
Backdoor Containment via Expert Quarantine and Shutdown in LLMs
Jianwei Li, Min-Seon Kim and Jung-Eun Kim
Backdoored large
language models (LLMs) can behave normally on benign inputs while producing attacker-specified outputs under hidden triggers. Existing defenses span four stages–prior-training, in-training, post-training, and inference-time–and share one of two underlying strategies: either suppress backdoor learning (by filtering poisoned data or interrupting its acquisition during optimization) or learn, then purify (by repairing model weights or gating inputs after a fully backdoored model has formed). We propose a third strategy, learn, but channel: allow backdoor formation during training but route it into a designated, quarantined component that can be disabled at deployment. To this end, we propose Quarantined Expert Shutdown QES, a computationally efficient containment strategy built in a regularization-steered MoE-like setting. Specifically, given a poisoned
dataset, QES augments a
Transformer-based
language model with routed expert-specific LoRA branches and lightweight routers, and uses auxiliary routing objectives to attract trigger-conditioned behavior into a designated expert while preserving benign capability elsewhere. At deployment, mitigation reduces to a single constant-time operation: zeroing the quarantined expert's routing weight, without trigger screening or further updating model weights. Empirically, our methods reduce the attack success rate ASR from 100% to 0-10% on most settings across two tasks, three attacks, and four model families, while downstream utility is often preserved or only modestly affected. These results establish learn, but channel as a previously unexplored regime for backdoor containment in generative LLMs.
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Cryptography and Security
Towards Hierarchical Cyber Defense with Large Language Models: From Planning to Execution
Harshith Doppalapudi, Nathaniel D. Bastian and Ankit Shah
An autonomous cyber defender trained with reinforcement learning (RL) is typically tied to the network on which it was trained, limiting its ability to generalize as network scale changes. Hierarchical RL reduces decision complexity by separating strategic targeting from tactical execution, but it does not eliminate this retraining dependence. We investigate whether frozen, zero-shot large
language models (LLMs) can provide retraining-free control in hierarchical cyber defense and how performance changes as LLM control is extended from planning to execution. We formulate a controller-agnostic planner-executor hierarchy in which the planner selects a subnet to defend over a fixed horizon and the executor selects defensive actions within that subnet. Using the high fidelity Cyberwheel environment, with its built-in automated red team
agent mapped to the MITRE ATT&CK framework, we compare RL+RL, LLM+RL, and LLM+LLM configurations using six models ranging from 3B to 70B parameters, including two cybersecurity-specialized models, across small, medium, and large networks. Replacing only the planner with an LLM yields limited gains as network size increases. In contrast, extending LLM control to execution produces notable improvements for sufficiently capable models. For instance, a frozen general purpose 70B model holds successful lateral movement to approximately 1% of steps and attacker impact near zero across all three network scales using the same model weights, while the RL baseline is retrained for each scale. Our results show that sufficiently capable frozen LLMs can maintain strong defensive performance across the evaluated network scales without task-specific retraining, while also indicating that strong tactical execution is important to realizing the benefits of LLM-based control.
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Cryptography and Security
No One Architecture Fits All: A Cross-Environment Evaluation of Hierarchical Red Team Agents
Ayan Javeed Shaikh, Arunesh Sinha, Nathaniel D. Bastian et al. (+1 more)
Autonomous red team
agents increasingly stress-test AI-enabled cyber defenses by planning strategy and executing multistage attacks. Reinforcement learning (RL) and large
language models (LLMs) offer complementary mechanisms for the planning and execution such
agents require, and prior work has combined them in hybrid hierarchies. Yet a given architecture is typically developed and evaluated within a single environment, leaving open whether an observed advantage reflects a generally stronger decision mechanism or merely
alignment with a particular setting. We address this gap with a controlled cross-environment comparison of two homogeneous hierarchical red team architectures: an RL planner with an RL executor (RL+RL) and an LLM planner with an LLM executor (LLM+LLM). We evaluate both against expert autonomous defenders in CybORG CAGE-4 and in Cyberwheel at two network scales, across 18 configurations under one unified disruption metric. We find a pronounced environment-dependent inversion. RL+RL wins the compact, densely rewarded CAGE-4 (78.5% disruption success versus 18.0% for the strongest LLM configuration) and the 100-host Cyberwheel network (81.0% versus 50.5%), while a pretrained cybersecurity LLM
agent wins the larger, escalation-gated 1010-host Cyberwheel network (55.0% versus 0.0% for RL). A kill-chain analysis explains the inversion through architecture-specific bottlenecks that aggregate success rates conceal.In the 1010-host Cyberwheel network, RL discovers and compromises hosts but stalls at privilege escalation, whereas in CAGE-4, LLM
agents obtain privileged access but rarely convert it into operational impact. These results indicate that conclusions drawn in a single environment may not generalize, and that hybrid planner-executor designs should be motivated by specific failure modes rather than the assumption that one architecture is universally preferable.
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All authors Ayan Javeed Shaikh, Arunesh Sinha, Nathaniel D. Bastian, Ankit Shah
Cryptography and Security
Harbormaster: Evidence-Gated, Replay-Safe Maritime Anomaly Detection on AWS
Arun Sharma
Ships broadcast their positions through the Automatic Identification System (AIS), and those reports can be false or missing. An operator who acts on an anomaly alert needs that alert to be attributable, reviewable, and recoverable after a failure. This paper describes Harbormaster, a production-shaped system on AWS that follows three rules. Physics checks run on every report before any learned model runs. The DynamoDB read store is an idempotent projection of PostgreSQL, and a guard on the log sequence number (LSN) of each change protects every write to it. A candidate model must pass a holdout gate and a shadow comparison before a canary gives it traffic, and a burn-rate check guards each canary step. The paper proves that replaying any prefix or suffix of the change log leaves each projected key at the value of its highest applied LSN. It also notes effects this result does not cover, such as repeated cache invalidations and repeated audit rows. In a bounded AWS window, a one-hour soak returned 35,999 HTTP 200 responses to 36,000 requests, with a 95th-percentile (p95) client latency of 142.751 ms. In a separate bounded AWS run of 900 s, the stream path received a burst of 400 records/s, and its consumer lag later drained to zero. Every number in the paper carries a label that says where it was measured, and the paper lists the parts of the design that were never built.
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Cryptography and Security · Cross-listed from quant-ph
Blind Unforgeability implies Plus-One Unforgeability
Mehil Agarwal, Calliope S. Reimann and Fang Song
We prove that
quantum blind-unforgeability implies
quantum plus-one unforgeability, settling an open question in the literature. Since plus-one unforgeability is known not to imply blind-unforgeability, our result establishes that blind-unforgeability is strictly stronger than plus-one unforgeability in the
quantum setting. The implication is proven using a new smoothing technique that coherently rescales the query histories of a
quantum-query
algorithm in a black-box manner. This enables us to transform any successful plus-one attacker into a blind-unforgeability attacker with only inverse-
polynomial loss. Our proof represents a conceptual shift from merely extracting a useful query history as in earlier attempts, which we show inevitably fails in general, to first coherently reshaping how query histories interfere.
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Cryptography and Security
ZoneClaw: Mitigating Persistent Memory Attacks by Establishing Memory-Zoning in OpenClaw-Style Computer-Use Agents
Haokai Ma, Chieh Lin, Yupeng Qiu et al. (+1 more)
Computer-use
agents increasingly operate as long-running assistants through persistent workspace
memory, which OpenClaw-style CUAs realize as automatically reloaded files that hold user instructions, system summaries, and external claims at the same privilege level. Here, remembering a claim confers authority over later behavior. This enables a persistent
memory attack, in which an attacker who controls only benign-looking external content induces the CUA to record attacker-favored claims during a legitimate task, and those claims later govern benign tasks the attacker never touches. The attack chain extends "malicious context -> malicious response" into "malicious context ->
memory injection -> malicious execution", making this a cross-environment threat. Existing defenses studied intervene either before content enters
memory or at the action it later induces, not whether stored content may guide action. We propose ZoneClaw, which separates persistence from authority by replacing flat workspace
memory with hierarchical trust zones carrying explicit authority levels. External claims persist in a low-trust zone and acquire action-guiding authority only by crossing an explicit authority boundary, at which promotion is cross-checked against zones the attacker cannot directly write. Role-specific processes of asymmetric privilege enforce this boundary, ensuring that no process both ingests external content and acts outward. Across four attack scenarios, two injection settings, and four backbones, ZoneClaw drives ASR from 372/480 to 6/480 while retaining utility in 458/480 trials, and remains effective against some defense-aware attackers. Attacker claims still persist in low-trust
memory yet rarely cross the authority boundary, showing that ZoneClaw withholds authority rather than refusing to learn from the environment. Our code is available at: https://github.com/euph00/ZoneClaw-code.
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All authors Haokai Ma, Chieh Lin, Yupeng Qiu, Ee-Chien Chang
Cryptography and Security · Cross-listed from quant-ph
Quantum Secret Sharing and Error Correction vs No-Cloning
Steven Chien, Ishani Mukherjee and Mark Zhandry
Secret sharing is ubiquitous throughout cryptography. All possible access structures are classically feasible, and in the case of threshold access structures, the protocols are even very efficient. However, when moving to the
quantum setting, the no-cloning
theorem shows that many access structures are impossible. In fact, no-cloning exactly characterizes feasibility: for thresholds,
quantum secret sharing is possible if and only if the threshold $t$ is strictly more than $n/2$. In this work, we propose a variant of
quantum secret sharing (QSS) where two or more identical copies of the input state are provided, but the output is only required to recover one copy. This notion circumvents the simple one-copy no-cloning obstruction, though the natural $k$-copy generalization still gives much milder obstructions. For thresholds using $k$ copies, no-cloning implies that QSS is impossible whenever $t\leq n/(k+1)$. It is tempting to hypothesize that no-cloning continues to exactly characterize the many-copy case. However, we show that this is not the case. We give positive results showing that multiple copies allow for going slightly beyond the single-copy obstruction: for thresholds, we construct QSS whenever $t>(n-k+1)/2$. On the other hand, we give a novel obstruction we call the Clique Path obstruction, which applies to arbitrary access structures. For thresholds, it shows that QSS is impossible whenever $t\leq (n-1)/k$. Our upper and lower bounds exactly match for $k=2$. Both our results leverage connections to the $k$-colorability of certain graphs derived from the access structure. We leave closing the gap for $k\geq 3$ copies as a fascinating direction for future work. Secret sharing is closely related to error correction, which can also be considered in the many-copy setting. Our results imply similar obstructions for
quantum error correction for erasure channels.
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Cryptography and Security · Cross-listed from cs.LG
Representation Transitions Reveal Emerging Safety Risks in Multi-Turn LLM Agents
Haoyu Wang, Wei Zhao, Yedi Zhang et al. (+2 more)
Multi-turn attacks on agentic systems can compose individually permissible actions into harmful outcomes, challenging defenses that assess actions or states in isolation. We show that such attacks leave a detectable signature in the
agent's internal representations: harmful behavior emerges as an accumulated representation transition across context updates, whose triggering context can be identified from the same signal. We further find that naive aggregation is confounded by benign representation drift, as a contrastive safety direction need not assign zero to benign transitions. We address this by denoising the direction, anchoring benign traffic at zero and removing its leading variation directions, with no runtime cost. These findings motivate DART, a runtime framework that detects and attributes representation shifts and intervenes with targeted reminders. Across six models and two multi-turn
benchmarks, DART reduces attack success from 84% to 25% on MT-AgentRisk, catching every attack at a mean false-alarm rate of 12%, and from 97% to 52% on ASEval, at costs in benign non-refusal of 8% and 0%, respectively. On MT-AgentRisk, it outperforms ToolShield, the state-of-the-art multi-turn defense, on all six models: under the same protocol, ToolShield reaches only 55%. Denoising is critical: on ASEval, the undenoised monitor catches only 7%-40% of attacks, while the denoised monitor catches 60%-85%. The same monitor covers single-turn indirect injection without modification and adds only 0.14-0.56 s overhead per monitored step without requiring an auxiliary model, making it a lightweight complement to computation-heavy speculative defenses.
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All authors Haoyu Wang, Wei Zhao, Yedi Zhang, Christopher M. Poskitt, Jun Sun