Daniel Alfasi

Monitoring medical data, e.g., Electrocardiogram (ECG) signals, is a common application of Internet of Things (IoT) devices. Compression methods are often applied on the massive amounts of sensor data generated prior to sending it to the Cloud to reduce the storage and delivery costs. A lossy compression provides high compression gain (CG), but may reduce the performance of an ECG application (downstream task) due to information loss. Previous works on ECG monitoring focus either on optimizing the signal reconstruction or the task’s performance. Instead, we advocate a self-adapting lossy compression solution that allows configuring a desired performance level on the downstream tasks while maintaining an optimized CG that reduces Cloud costs.
We propose Dynamic-Deep, a task-aware compression geared for IoT-Cloud architectures. Our compressor is trained to optimize the CG while maintaining the performance requirement of the downstream tasks chosen out of a wide range. In deployment, the IoT edge device adapts the compression and sends an optimized representation for each data segment, accounting for the downstream task’s desired performance without relying on feedback from the Cloud. We conduct an extensive evaluation of our approach on common ECG datasets using two popular ECG applications, which includes heart rate (HR) arrhythmia classification. We demonstrate that Dynamic-Deep can be configured to improve HR classification F1-score in a wide range of requirements. One of which is tuned to improve the F1-score by 3 and increases CG by up to 83% compared to the previous state of-the-art (autoencoder-based) compressor. Analyzing DynamicDeep on the Google Cloud Platform, we observe a 97% reduction in cloud costs compared to a no compression solution. To the best of our knowledge, Dynamic-Deep is the first end-to end system architecture proposal to focus on balancing the need for high performance of cloud-based downstream tasks and the desire to achieve optimized compression in IoT ECG monitoring settings.

Analyzing the network behavior of IoT devices, including which domains, protocols, and ports the device communicates with, is a fundamental challenge for IoT security and identification. Solutions that analyze and manage these areas must be able to learn what constitutes normal device behavior and then extract rules and features to permit only legitimate behavior or identify the device. The Manufacturer Usage Description (MUD) is an IETF white-list protection scheme that formalizes the authorized network behavior in a MUD file; this MUD file can then be used as a type of firewall mechanism.

We demonstrate that learning what is normal behavior for an IoT device is more challenging than expected. In many cases, the same IoT device, with the same firmware, can exhibit different behavior or connect to different domains with different protocols, depending on the device’s geographical location.

Then, we present a technique to generalize MUD files. By processing MUD files that originate in different locations, we can generalize and create a comprehensive MUD file that is applicable for all locations.
To conduct the research, we created MUDIS, a MUD Inspection System tool, that compares and generalizes MUD files. Our open-source MUDIS tool and dataset are available online to researchers and IoT manufacturers, allowing anyone to visualize, compare, and generalize MUD files.

Distributed denial of service (DDoS) attacks, especially distributed reflection denial of service attacks (DRDoS), have increased dramatically in frequency and volume in recent years. Such attacks are possible due to the attacker’s ability to spoof the source address of IP packets. Since the early days of the internet, authenticating the IP source address has remained unresolved in the real world. Although there are many methods available to eliminate source spoofing, they are not widely used, primarily due to a lack of economic incentives.
We propose a collaborative on-demand route-based defense technique (CORB) to offer efficient DDoS mitigation as a paid-for-service, and efficiently assuage reflector attacks before they reach the reflectors and flood the victim. The technique uses scrubbing facilities located across the internet at internet service providers (ISPs) and internet exchange points (IXPs).
By transmitting a small amount of data based on border gateway protocol (BGP) information from the victim to the scrubbing facilities, we can filter out the attack without any false-positive cases. For example, the data can be sent using DOTS, a new signaling DDoS protocol that was standardized by the IETF. CORB filters the attack before it is amplified by the reflector, thereby reducing the overall cost of the attack. This provides a win-win financial situation for the victim and the scrubbing facilities that provide the service.
We demonstrate the value of CORB by simulating a Memcached DRDoS attack using real-life data. Our evaluation found that deploying CORB on scrubbing facilities at approximately 40 autonomous systems blocks 90% of the attack and can reduce the mitigation cost by 85%.

We investigate the negative caching (caching of NXdomain
responses) behavior on nine large open DNS resolvers. We
measure the amount of time an NXDomain response is kept
in the cache in various TTL configurations and compare it
to the time an existent domain is kept in the cache.