Hello and welcome back to the course. In this section will take a look at Alibaba Clouds. Security products will have an overview of host data network and application security. But before that, we'll start with a brief introduction. I want to introduce you to Ali Baba Clouds Platform security model. So what do I mean by that? Well, I'm talking about the shared responsibility model that we use to separate customer responsibilities from Alibaba Cloud responsibilities, which you can see in this diagram. Here at the bottom layer in yellow, we have things that are the responsibility of Ali Baba Cloud. So from a security standpoint, Ali Baba Cloud is responsible for the physical security of our data centers. The security of the hardware in those data centers the security of the cloud platform itself the integrity of the account system that you used to log in the security of each cloud service that we build and deploy and then virtualization layer security. So the security of the service that launches and schedules virtual machines, all those things in yellow, at the bottom are Alibaba clouds responsibility. On top of that, we have things that are the customers responsibility So you, as a user of Ali Baba Cloud, need to worry about the things in orange. If you have a security issue with any of the things shown in orange here, then the responsibility to resolve that security issue falls on you. That includes data security, network security, virtual machine security. That means security of the operating system in the VM application security. So the security of any applications you've deployed operational security. So who is allowed to do what and when you're responsible for setting those permissions and business security? You need to make sure that you understand the risks that apply to the application that you want to deploy and that your business structure and logic is built in a way where your application can sustainably run without any major security incidents. Those things air all your responsibility. As the customer, we will help you deal with the hardware, physical and platform security underneath of all that. So here we see the Ali Baba Cloud Security architecture in a little bit mawr detail, so you can see it again. At the very bottom, there's cloud platform security. Those things are Alibaba's responsibility on then on top of that, there's user infrastructure, user data, user application, user business. Those things are the users responsibility. So you need again ensure that any containers or VMS you're running are safe, that their network configuration is compliant and safe. That you're using encryption to secure data at rest, etcetera, etcetera, user account security. Although it's not easy to tell from this slide and the previous slide user account, security is a shared responsibility. The security and integrity of the Ali Baba Cloud account system is our responsibility. But of course, as the user, it's your responsibility to turn on multi factor authentication and choose a strong password. And be careful about who you grant privileges to when you create RAM users. Then there's user security monitoring and operations all the way on the right. I want to point this out because thes air products that we provide to help you mitigate the workload associated with managing your own security so you can see that quite a lot of the security responsibility falls on you as the user. All the applications you're running, the patching and updating of the virtual machines that you that you're running all of that falls on you as the user. So what tools can we provide you to help you stay safe to help you detect and mitigate threats? Well, there's quite a few. We offer penetration, testing, security consulting and then also a log audit service, baseline configuration checking and several kinds of threat detection and response tools, most of which can be automated. So you're not on your own. We do have tools to help you manage some of these security problems that you might encounter, although at its heart it might seem like Alibaba Group is an e commerce company were really a data company, and Alibaba Cloud is on the forefront of protecting our user data from Attackers. We currently lead the cloud security market in China. We protect 40% of websites that are hosted here. We mitigate 3.6 billion yes, billion attacks each day and we defend against upwards of 1500 DDOS attacks every day, with the total volume of more than a terabyte per second on average. That's the 2018 figure. It's probably higher now, and we quarantine something like 140,000 malicious files that we detect being installed on the C S instances each day again. That's for users who have failed to secure their instances. They may be vulnerable to viruses and Trojans, and we have a security center tool that can help them to detect act, and it does more than 140,000 times a day. It helps protect users against Trojans viruses and other malicious software being installed on their PCs instances. Our security expertise comes from our own hard won experience. We've now been running the Double 11 sales Festival for more than 10 years, and we have multiple, different Alibaba Business Unit, depending on Alibaba Cloud to keep them up and running. That includes China for logistics, all of our e commerce platforms, Ali Baba Ali Express, 16 88 Timo and Tao Bao, as well as and financial, which it is in charge of Microloans Ali pay insurance on also several other banking related products. So all three of those major components within the company all depend on Alibaba Cloud for security on last year's Double 11 Excuse me 2018, Double 11 alone. We received attack traffic from more than 194 different countries. China included of course, with over 5000 details attacks launched during that single day. So as you can see, we're a very popular attack target during the Double 11 sail up, over and above our usual high level of attacks that we experience day to day. On that one day we received over two billion attacks from the public Internet. And despite that high level of attacks, we were still able to keep our service up and running smoothly for our users with no data loss and no downtime. So now that I've painted a picture of Ali Baba clouds own security background, let's get into host security and see what capabilities we can offer to end users in that domain.