Federated learning enables a large number of clients (such as edge computing devices) to learn a model jointly without data sharing. However, the high amount of communication of the federated learning aggregation algorithm hinders the realisation of artificial intelligence in the last mile. Although FederatedAveraging (FedAvg) is the leading algorithm, its communication cost is still high. The method of communication delay and gradient sparse can reduce the communication cost, but there is no previous work to analyse the relationship and common effects of these two dimensions. Aiming at the problems that federated learning communication is expensive and it has become a training bottleneck, we improve the FedAvg algorithm and propose an adaptive communication frequency FederatedAveraging algorithm (AFedAvg). The gradient sparse operation in the algorithm reduces the quantity of parameters for a single communication, while the communication delay operation allows training to converge faster and obtain smaller losses. The number of sparse parameters is used to select the communication frequency of next round dynamically. Experimental results prove that, the AFedAvg algorithm is superior to the FedAvg and its variants in terms of communication cost. It achieves 2.4X–23.1X communication compression in different data distributions with minimal communication rounds required by the algorithm to converge.

While side-channel attacks (SCAs) have become a significant threat to cryptographic algorithms, masking is considered as an effective countermeasure against SCAs. On the one hand, securely implementing the scheme is a challenging and error-prone task. It is essential to detect leakage in a complicated cryptographic circuit. However, the traditional method of leakage detection is always inaccuracy or time consumption. On the other hand, the deep learning-based power attacks have shown their threat to the masking without combining functions. Compared to the leakage detection done under the traditional provable security framework, the security evaluation against deep learning-based attacks at the pre-silicon stage has not been discussed. To this end, this paper investigates the strategies of leveraging the deep learning techniques to achieve an efficient leakage location method. In this paper, we present the first approach utilizing deep learning-based leakage location for both unprotected and protected implementations at the pre-silicon stage. Firstly, we propose the leakage location method named Gradient Visualization-based location (GVL), which provides leakage location at the different levels of design. Gradient visualization is known as a sensitivity analysis method to understand better how a natural network can learn to predict the sensitive label based on the input. We theoretically show how the gradient visualization can be used to locate leakage components in the netlist efficiently. Moreover, we link the result with the metric in deep learning-based leakage assessment, which fills the lack of leakage evaluation at the pre-silicon stage against deep learning-based SCAs. We further confirm the effectiveness of the proposed method on unprotected implementation, low entropy masked implementation, and provable secure masked implementation. The results show that the proposed methodology outperforms the traditional location methods in the masked cases, where the time consumption is reduced by about 2x to 10x with fewer false negatives and no false positives.

The widely deployed devices in Internet of Things (IoT) have opened up a large amount of IoT data. Recently, federated learning emerges as a promising solution aiming to protect user privacy on IoT devices by training a globally shared model. However, the devices in the complex IoT environments pose great challenge to federate learning, which is vulnerable to gradient-based reconstruction attacks. In this paper, we discuss the relationships between the security of federated learning model and optimization technologies of decreasing communication overhead comprehensively. To promote the efficiency and security, we propose a defence strategy of federated learning which is suitable to resource-constrained IoT devices. The adaptive communication strategy is to adjust the frequency and parameter compression by analysing the training loss to ensure the security of the model. The experiments show the efficiency of our proposed method to decrease communication overhead, while preventing privacy data leakage.

The network I/O operations of a guest domain spend Domain0's processor resource as well as its own processor resource. If no control is placed on the network I/O operations of guest domains, Xen system will likely overload when executing network I/O-intensive workload. To resolve this problem, the allowable network I/O request number of Xen system should be firstly figured out. This paper illuminated the characteristic of Xen system in handling the network I/O operations of guest domains with two experimental results, and established several performance analyzing and predicting models by studying the network I/O procedure and the processor resource consumption distribution of Xen system. These models can compute the allowable number of guest domains with fixed network I/O request number or the allowable network I/O request number of each guest domain based on all idle processor resource of Xen system, and prevent Xen system from overloading. Finally, the applicability of these models is preliminarily analyzed.