对多代理后门攻击的最新探索表明了反击效应,这是对后门攻击的自然防御效果,后门攻击是随机分类的。这产生了低精度W.R.T.的副作用干净的标签,激发本文在构建多代理后门防御的构建方面的工作,该防御能力最大化精确度W.R.T.清洁标签并将毒药标签的标签降至最低。我们建立在代理动力学和低损失子空间结构的基础上,我们贡献了三种防御能力,可提高多代理后门鲁棒性。
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NLP系统的Black-Box对抗攻击中最近的工作引起了很多关注。先前的黑框攻击假设攻击者可以根据选定的输入观察目标模型的输出标签。在这项工作中,受到对抗性转移性的启发,我们提出了一种新型的黑盒NLP对抗性攻击,攻击者可以选择相似的域并将对抗性示例转移到目标域并在目标模型中导致性能差。基于领域的适应理论,我们提出了一种称为Learn2Weight的防御策略,该策略训练以预测目标模型的重量调整,以防止对类似的对抗性示例的攻击。使用亚马逊多域情绪分类数据集,我们从经验上表明,与标准的黑盒防御方法(例如对抗性训练和防御性蒸馏)相比,Learn2Weight对攻击有效。这项工作有助于越来越多的有关机器学习安全的文献。
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随着机器学习数据的策展变得越来越自动化,数据集篡改是一种安装威胁。后门攻击者通过培训数据篡改,以嵌入在该数据上培训的模型中的漏洞。然后通过将“触发”放入模型的输入中的推理时间以推理时间激活此漏洞。典型的后门攻击将触发器直接插入训练数据,尽管在检查时可能会看到这种攻击。相比之下,隐藏的触发后托攻击攻击达到中毒,而无需将触发器放入训练数据即可。然而,这种隐藏的触发攻击在从头开始培训的中毒神经网络时无效。我们开发了一个新的隐藏触发攻击,睡眠代理,在制备过程中使用梯度匹配,数据选择和目标模型重新培训。睡眠者代理是第一个隐藏的触发后门攻击,以对从头开始培训的神经网络有效。我们展示了Imagenet和黑盒设置的有效性。我们的实现代码可以在https://github.com/hsouri/sleeper-agent找到。
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Open software supply chain attacks, once successful, can exact heavy costs in mission-critical applications. As open-source ecosystems for deep learning flourish and become increasingly universal, they present attackers previously unexplored avenues to code-inject malicious backdoors in deep neural network models. This paper proposes Flareon, a small, stealthy, seemingly harmless code modification that specifically targets the data augmentation pipeline with motion-based triggers. Flareon neither alters ground-truth labels, nor modifies the training loss objective, nor does it assume prior knowledge of the victim model architecture, training data, and training hyperparameters. Yet, it has a surprisingly large ramification on training -- models trained under Flareon learn powerful target-conditional (or "any2any") backdoors. The resulting models can exhibit high attack success rates for any target choices and better clean accuracies than backdoor attacks that not only seize greater control, but also assume more restrictive attack capabilities. We also demonstrate the effectiveness of Flareon against recent defenses. Flareon is fully open-source and available online to the deep learning community: https://github.com/lafeat/flareon.
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最近的研究表明,深神经网络(DNN)易受对抗性攻击的影响,包括逃避和后门(中毒)攻击。在防守方面,有密集的努力,改善了对逃避袭击的经验和可怜的稳健性;然而,对后门攻击的可稳健性仍然很大程度上是未开发的。在本文中,我们专注于认证机器学习模型稳健性,反对一般威胁模型,尤其是后门攻击。我们首先通过随机平滑技术提供统一的框架,并展示如何实例化以证明对逃避和后门攻击的鲁棒性。然后,我们提出了第一个强大的培训过程Rab,以平滑训练有素的模型,并证明其稳健性对抗后门攻击。我们派生机学习模型的稳健性突出了培训的机器学习模型,并证明我们的鲁棒性受到紧张。此外,我们表明,可以有效地训练强大的平滑模型,以适用于诸如k最近邻分类器的简单模型,并提出了一种精确的平滑训练算法,该算法消除了从这种模型的噪声分布采样采样的需要。经验上,我们对MNIST,CIFAR-10和Imagenet数据集等DNN,差异私有DNN和K-NN模型等不同机器学习(ML)型号进行了全面的实验,并为反卧系攻击提供认证稳健性的第一个基准。此外,我们在SPAMBase表格数据集上评估K-NN模型,以展示所提出的精确算法的优点。对多元化模型和数据集的综合评价既有关于普通训练时间攻击的进一步强劲学习策略的多样化模型和数据集的综合评价。
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本文提出了针对回顾性神经网络(Badnets)的新型两级防御(NNOCULICULE),该案例在响应该字段中遇到的回溯测试输入,修复了预部署和在线的BADNET。在预部署阶段,NNICULICULE与清洁验证输入的随机扰动进行检测,以部分减少后门的对抗影响。部署后,NNOCULICULE通过在原始和预先部署修补网络之间录制分歧来检测和隔离测试输入。然后培训Constcan以学习清洁验证和隔离输入之间的转换;即,它学会添加触发器来清洁验证图像。回顾验证图像以及其正确的标签用于进一步重新培训预修补程序,产生我们的最终防御。关于全面的后门攻击套件的实证评估表明,NNOCLICULE优于所有最先进的防御,以制定限制性假设,并且仅在特定的后门攻击上工作,或者在适应性攻击中失败。相比之下,NNICULICULE使得最小的假设并提供有效的防御,即使在现有防御因攻击者而导致其限制假设而导致的现有防御无效的情况下。
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后门攻击已被证明是对深度学习模型的严重安全威胁,并且检测给定模型是否已成为后门成为至关重要的任务。现有的防御措施主要建立在观察到后门触发器通常尺寸很小或仅影响几个神经元激活的观察结果。但是,在许多情况下,尤其是对于高级后门攻击,违反了上述观察结果,阻碍了现有防御的性能和适用性。在本文中,我们提出了基于新观察的后门防御范围。也就是说,有效的后门攻击通常需要对中毒训练样本的高预测置信度,以确保训练有素的模型具有很高的可能性。基于此观察结果,Dtinspector首先学习一个可以改变最高信心数据的预测的补丁,然后通过检查在低信心数据上应用学习补丁后检查预测变化的比率来决定后门的存在。对五次后门攻击,四个数据集和三种高级攻击类型的广泛评估证明了拟议防御的有效性。
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As a critical threat to deep neural networks (DNNs), backdoor attacks can be categorized into two types, i.e., source-agnostic backdoor attacks (SABAs) and source-specific backdoor attacks (SSBAs). Compared to traditional SABAs, SSBAs are more advanced in that they have superior stealthier in bypassing mainstream countermeasures that are effective against SABAs. Nonetheless, existing SSBAs suffer from two major limitations. First, they can hardly achieve a good trade-off between ASR (attack success rate) and FPR (false positive rate). Besides, they can be effectively detected by the state-of-the-art (SOTA) countermeasures (e.g., SCAn). To address the limitations above, we propose a new class of viable source-specific backdoor attacks, coined as CASSOCK. Our key insight is that trigger designs when creating poisoned data and cover data in SSBAs play a crucial role in demonstrating a viable source-specific attack, which has not been considered by existing SSBAs. With this insight, we focus on trigger transparency and content when crafting triggers for poisoned dataset where a sample has an attacker-targeted label and cover dataset where a sample has a ground-truth label. Specifically, we implement $CASSOCK_{Trans}$ and $CASSOCK_{Cont}$. While both they are orthogonal, they are complementary to each other, generating a more powerful attack, called $CASSOCK_{Comp}$, with further improved attack performance and stealthiness. We perform a comprehensive evaluation of the three $CASSOCK$-based attacks on four popular datasets and three SOTA defenses. Compared with a representative SSBA as a baseline ($SSBA_{Base}$), $CASSOCK$-based attacks have significantly advanced the attack performance, i.e., higher ASR and lower FPR with comparable CDA (clean data accuracy). Besides, $CASSOCK$-based attacks have effectively bypassed the SOTA defenses, and $SSBA_{Base}$ cannot.
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Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.
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计算能力和大型培训数据集的可用性增加,机器学习的成功助长了。假设它充分代表了在测试时遇到的数据,则使用培训数据来学习新模型或更新现有模型。这种假设受到中毒威胁的挑战,这种攻击会操纵训练数据,以损害模型在测试时的表现。尽管中毒已被认为是行业应用中的相关威胁,到目前为止,已经提出了各种不同的攻击和防御措施,但对该领域的完整系统化和批判性审查仍然缺失。在这项调查中,我们在机器学习中提供了中毒攻击和防御措施的全面系统化,审查了过去15年中该领域发表的100多篇论文。我们首先对当前的威胁模型和攻击进行分类,然后相应地组织现有防御。虽然我们主要关注计算机视觉应用程序,但我们认为我们的系统化还包括其他数据模式的最新攻击和防御。最后,我们讨论了中毒研究的现有资源,并阐明了当前的局限性和该研究领域的开放研究问题。
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A recent trojan attack on deep neural network (DNN) models is one insidious variant of data poisoning attacks. Trojan attacks exploit an effective backdoor created in a DNN model by leveraging the difficulty in interpretability of the learned model to misclassify any inputs signed with the attacker's chosen trojan trigger. Since the trojan trigger is a secret guarded and exploited by the attacker, detecting such trojan inputs is a challenge, especially at run-time when models are in active operation. This work builds STRong Intentional Perturbation (STRIP) based run-time trojan attack detection system and focuses on vision system. We intentionally perturb the incoming input, for instance by superimposing various image patterns, and observe the randomness of predicted classes for perturbed inputs from a given deployed model-malicious or benign. A low entropy in predicted classes violates the input-dependence property of a benign model and implies the presence of a malicious input-a characteristic of a trojaned input. The high efficacy of our method is validated through case studies on three popular and contrasting datasets: MNIST, CIFAR10 and GTSRB. We achieve an overall false acceptance rate (FAR) of less than 1%, given a preset false rejection rate (FRR) of 1%, for different types of triggers. Using CIFAR10 and GTSRB, we have empirically achieved result of 0% for both FRR and FAR. We have also evaluated STRIP robustness against a number of trojan attack variants and adaptive attacks.
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许多最先进的ML模型在各种任务中具有优于图像分类的人类。具有如此出色的性能,ML模型今天被广泛使用。然而,存在对抗性攻击和数据中毒攻击的真正符合ML模型的稳健性。例如,Engstrom等人。证明了最先进的图像分类器可以容易地被任意图像上的小旋转欺骗。由于ML系统越来越纳入安全性和安全敏感的应用,对抗攻击和数据中毒攻击构成了相当大的威胁。本章侧重于ML安全的两个广泛和重要的领域:对抗攻击和数据中毒攻击。
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有针对性的训练集攻击将恶意实例注入训练集中,以导致训练有素的模型错误地标记一个或多个特定的测试实例。这项工作提出了目标识别的任务,该任务决定了特定的测试实例是否是训练集攻击的目标。目标识别可以与对抗性识别相结合,以查找(并删除)攻击实例,从而减轻对其他预测的影响,从而减轻攻击。我们没有专注于单个攻击方法或数据模式,而是基于影响力估计,这量化了每个培训实例对模型预测的贡献。我们表明,现有的影响估计量的不良实际表现通常来自于他们对训练实例和迭代次数的过度依赖。我们重新归一化的影响估计器解决了这一弱点。他们的表现远远超过了原始估计量,可以在对抗和非对抗环境中识别有影响力的训练示例群体,甚至发现多达100%的对抗训练实例,没有清洁数据误报。然后,目标识别简化以检测具有异常影响值的测试实例。我们证明了我们的方法对各种数据域的后门和中毒攻击的有效性,包括文本,视觉和语音,以及针对灰色盒子的自适应攻击者,该攻击者专门优化了逃避我们方法的对抗性实例。我们的源代码可在https://github.com/zaydh/target_indistification中找到。
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Adaptive attacks have (rightfully) become the de facto standard for evaluating defenses to adversarial examples. We find, however, that typical adaptive evaluations are incomplete. We demonstrate that thirteen defenses recently published at ICLR, ICML and NeurIPS-and which illustrate a diverse set of defense strategies-can be circumvented despite attempting to perform evaluations using adaptive attacks. While prior evaluation papers focused mainly on the end result-showing that a defense was ineffective-this paper focuses on laying out the methodology and the approach necessary to perform an adaptive attack. Some of our attack strategies are generalizable, but no single strategy would have been sufficient for all defenses. This underlines our key message that adaptive attacks cannot be automated and always require careful and appropriate tuning to a given defense. We hope that these analyses will serve as guidance on how to properly perform adaptive attacks against defenses to adversarial examples, and thus will allow the community to make further progress in building more robust models.
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将模型参数适应传入数据流是深度学习可伸缩性的关键因素。有趣的是,在线设置中的先前持续学习策略无意中将其更新的参数锚定在本地参数子空间中,以记住旧任务,否则会偏离子空间并忘记。从这个观察结果,我们在构建多个参数模式和每个模式分配任务之间建立了权衡。模式优化的任务分配(MOTA),我们的贡献适应策略,并行训练多个模式,然后优化每个模式的任务分配。我们从经验上证明了基线连续学习策略以及各种分配变化的改进,即子人群,领域和任务转变。
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在对抗机器学习中,防止对深度学习系统的攻击的新防御能力在释放更强大的攻击后不久就会破坏。在这种情况下,法医工具可以通过追溯成功的根本原因来为现有防御措施提供宝贵的补充,并为缓解措施提供前进的途径,以防止将来采取类似的攻击。在本文中,我们描述了我们为开发用于深度神经网络毒物攻击的法医追溯工具的努力。我们提出了一种新型的迭代聚类和修剪解决方案,该解决方案修剪了“无辜”训练样本,直到所有剩余的是一组造成攻击的中毒数据。我们的方法群群训练样本基于它们对模型参数的影响,然后使用有效的数据解读方法来修剪无辜簇。我们从经验上证明了系统对三种类型的肮脏标签(后门)毒物攻击和三种类型的清洁标签毒药攻击的功效,这些毒物跨越了计算机视觉和恶意软件分类。我们的系统在所有攻击中都达到了98.4%的精度和96.8%的召回。我们还表明,我们的系统与专门攻击它的四种抗纤维法措施相对强大。
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由于其便利性,使用第三方提供的预培训模型变得越来越普遍。然而,与此同时,这些模型可能容易受到中毒和逃避攻击的影响。我们引入了一个算法框架,当防御者无法获得清洁数据时,可以在预训练的模型中减轻潜在的安全漏洞。框架从给定的预训练模型进行了反向工程。然后,可以将所得的合成样品用作替代干净的数据以执行各种防御措施。我们考虑两种重要的攻击场景 - 后门攻击和逃避攻击 - 以展示合成样本的实用性。对于这两次攻击,我们表明,当提供我们的合成数据时,最新的防御能力的性能相当甚至比提供相同数量的清洁数据时的情况相当甚至更好。
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Backdoor attacks have emerged as one of the major security threats to deep learning models as they can easily control the model's test-time predictions by pre-injecting a backdoor trigger into the model at training time. While backdoor attacks have been extensively studied on images, few works have investigated the threat of backdoor attacks on time series data. To fill this gap, in this paper we present a novel generative approach for time series backdoor attacks against deep learning based time series classifiers. Backdoor attacks have two main goals: high stealthiness and high attack success rate. We find that, compared to images, it can be more challenging to achieve the two goals on time series. This is because time series have fewer input dimensions and lower degrees of freedom, making it hard to achieve a high attack success rate without compromising stealthiness. Our generative approach addresses this challenge by generating trigger patterns that are as realistic as real-time series patterns while achieving a high attack success rate without causing a significant drop in clean accuracy. We also show that our proposed attack is resistant to potential backdoor defenses. Furthermore, we propose a novel universal generator that can poison any type of time series with a single generator that allows universal attacks without the need to fine-tune the generative model for new time series datasets.
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与令人印象深刻的进步触动了我们社会的各个方面,基于深度神经网络(DNN)的AI技术正在带来越来越多的安全问题。虽然在考试时间运行的攻击垄断了研究人员的初始关注,但是通过干扰培训过程来利用破坏DNN模型的可能性,代表了破坏训练过程的可能性,这是破坏AI技术的可靠性的进一步严重威胁。在后门攻击中,攻击者损坏了培训数据,以便在测试时间诱导错误的行为。然而,测试时间误差仅在存在与正确制作的输入样本对应的触发事件的情况下被激活。通过这种方式,损坏的网络继续正常输入的预期工作,并且只有当攻击者决定激活网络内隐藏的后门时,才会发生恶意行为。在过去几年中,后门攻击一直是强烈的研究活动的主题,重点是新的攻击阶段的发展,以及可能对策的提议。此概述文件的目标是审查发表的作品,直到现在,分类到目前为止提出的不同类型的攻击和防御。指导分析的分类基于攻击者对培训过程的控制量,以及防御者验证用于培训的数据的完整性,并监控DNN在培训和测试中的操作时间。因此,拟议的分析特别适合于参考他们在运营的应用方案的攻击和防御的强度和弱点。
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从外界培训的机器学习模型可能会被数据中毒攻击损坏,将恶意指向到模型的培训集中。对这些攻击的常见防御是数据消毒:在培训模型之前首先过滤出异常培训点。在本文中,我们开发了三次攻击,可以绕过广泛的常见数据消毒防御,包括基于最近邻居,训练损失和奇异值分解的异常探测器。通过增加3%的中毒数据,我们的攻击成功地将Enron垃圾邮件检测数据集的测试错误从3%增加到24%,并且IMDB情绪分类数据集从12%到29%。相比之下,没有明确占据这些数据消毒防御的现有攻击被他们击败。我们的攻击基于两个想法:(i)我们协调我们的攻击将中毒点彼此放置在彼此附近,(ii)我们将每个攻击制定为受限制的优化问题,限制旨在确保中毒点逃避检测。随着这种优化涉及解决昂贵的Bilevel问题,我们的三个攻击对应于基于影响功能的近似近似这个问题的方式; minimax二元性;和karush-kuhn-tucker(kkt)条件。我们的结果强调了对数据中毒攻击产生更强大的防御的必要性。
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